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5
895
Given that \(AD\), \(BE\), and \(CF\) are the altitudes of the acute triangle \(\triangle ABC\). If \(AB = 26\) and \(\frac{EF}{BC} = \frac{5}{13}\), calculate the length of \(BE\).
24
math
63
Given a triangle $\triangle ABC$ with vertices at $A(0,1)$, $B(2,1)$, and $C(3,4)$: 1. Find the equation of the circumcircle of $\triangle ABC$. 2. If one endpoint $N$ of a line segment $MN$ is at $(6,2)$ and the other endpoint $M$ moves along the circumcircle of $\triangle ABC$, find the equation of the locus of the m...
\left(x-\frac{7}{2}\right)^2+\left(y-\frac{5}{2}\right)^2=\frac{5}{4}
math
108
Given a sequence $\left\{ a_n \right\}$ that satisfies for any $n\in N^{*}$, we have $a_1^3+a_2^3+\cdots +a_n^3=(a_1+a_2+\cdots +a_n)^2$, and $a_n > 0$. (1) Find the general formula for the sequence $\left\{ a_n \right\}$. (2) Let the sum of the first $n$ terms of the sequence $\left\{ \frac{1}{a_n\cdot a_{n+2}} \...
(0, \frac{1}{2})
math
176
Given the vector $ \vec{a}=(-3,4) $, calculate the magnitude of $\vec{a}$.
5
math
26
If a hyperbola passes through the point $(3,\sqrt{2})$, and its asymptote equations are $y=\pm\frac{1}{3}x$, determine the equation of this hyperbola.
y^2-\frac{x^2}{9}=1
math
45
Let \( P(x) \) be a polynomial of degree \( 2n \) such that: \[ \begin{array}{l} P(0) = P(2) = \cdots = P(2n) = 0, \\ P(1) = P(3) = \cdots = P(2n-1) = 2, \\ P(2n+1) = -6. \end{array} \] Determine \( n \) and \( P(x) \).
P(x) = -2x^2 + 4x
math
111
A rectangular wooden block is 6 inches long, 3 inches wide, and 2 inches high. The block is painted blue on all six sides and then cut into 1 inch cubes. How many of the cubes each have a total number of blue faces that is an even number?
20
math
58
By expanding the expression \((1+\sqrt{11})^{214}\) using the binomial theorem, we obtain terms of the form \(C_{214}^{k}(\sqrt{11})^{k}\). Find the value of \( k \) for which this term has the greatest value.
165
math
68
The coefficient of $x^2$ in the expansion of $(x^2+x+1)(1-x)^4$ is __________.
3
math
29
Given the one-variable quadratic equation in $x$, $(k+2)x^{2}-2x-1=0$, determine the range of real number $k$ for which the equation has real roots.
k\geqslant -3 \text{ and } k\neq -2
math
42
A ferry boat transports visitors to a resort starting at 9 AM until the final ride at 5 PM, on an hourly schedule. On the initial 9 AM trip, there are 120 visitors and with each subsequent trip, the number of visitors decreases by 2. Determine the total number of visitors carried to the resort that particular day.
1008
math
71
Given that $f'(x_0) = a$, evaluate the limit $$\lim_{△x \to 0} \frac{f(x_0 + △x) - f(x_0 - 3△x)}{2△x}.$$
2a
math
55
Given a school with 1680 students, where 84 individuals are systematically sampled and their numbers fall within the range from 61 to 160 inclusive, calculate the number of sampled individuals.
5
math
44
For \(a, b, c > 0\), find the maximum value of the expression \[ A=\frac{a^{2}(b+c)+b^{2}(c+a)+c^{2}(a+b)}{a^{3}+b^{3}+c^{3}-2 abc} \]
6
math
67
What is the value of $$ (x+1)(x+2006)\left[\frac{1}{(x+1)(x+2)}+\frac{1}{(x+2)(x+3)}+\ldots+\frac{1}{(x+2005)(x+2006)}\right] ? $$
2005
math
76
Given the hyperbola $\frac{x^2}{a^2} - \frac{y^2}{b^2} = 1$ ($a > 0, b > 0$), if the endpoints of the real axis and the endpoints of the imaginary axis of the hyperbola exactly form a square, calculate the eccentricity of this hyperbola.
\sqrt{2}
math
77
Given four unequal, positive integers \(a, b, c,\) and \(N\) where \(N=5a+3b+5c\), \(N=4a+5b+4c\), and \(N\) is between 131 and 150, calculate the value of \(a+b+c\).
33
math
71
In triangle $ABC$, the sides opposite to angles $A$, $B$, and $C$ are denoted as $a$, $b$, and $c$ respectively. It is given that $2a= \sqrt{3}c\sin A-a\cos C$. $(1)$ Find $C$; $(2)$ If $c= \sqrt{3}$, find the maximum value of the area $S$ of triangle $ABC$.
\dfrac{\sqrt{3}}{4}
math
96
A number $x$ has the property that $x\%$ of $x$ is $4$. Solve for $x$.
20
math
27
Consider the three lines given by the equations \(2y - 3x = 4\), \(3x + 4y = 6\), and \(6x - 9y = 8\). Determine the number of points that lie at the intersection of at least two of these lines.
2
math
63
Consider two points on the surface of a sphere, representing Earth. Point $A$ is located at $0^\circ$ latitude and $90^\circ \text{ E}$ longitude, and point $B$ is at $30^\circ \text{ N}$ latitude and $90^\circ \text{ W}$ longitude. Calculate the degree measure of $\angle ACB$ where $C$ is the center of the Earth.
150^\circ
math
91
When the decimal point of a certain positive decimal number is moved three places to the right, the new number becomes three times the reciprocal of the original number. What is the original number?
\frac{\sqrt{30}}{100}
math
37
A circle with the equation $x^2 + y^2 - 8x - 6y + 24 = 0$ is inscribed inside a square that has a pair of sides parallel to the x-axis. What is the area of this square?
4
math
55
A $\emph{convex}$ polygon is a polygon in which every interior angle is less than 180 degrees. A $\emph{diagonal}$ is a line segment that connects two non-adjacent vertices. Calculate how many diagonals a convex polygon with 25 sides has. Additionally, calculate the sum of all the interior angles in this polygon.
4140
math
76
Given f(x)=x^{2}+2xf'(-1), calculate f'(0).
4
math
20
Given $\tan \alpha=4$, calculate the value of $\frac{1+\cos 2\alpha+8\sin^2\alpha}{\sin 2\alpha}$.
\frac{65}{4}
math
39
A set of $n$ numbers has the sum $s$. Each number of the set is increased by $30$, then multiplied by $3$, and finally decreased by $10$. The sum of the numbers in the new set is: **A)** $3s + 80n$ **B)** $3s + 70n$ **C)** $s + 110n$ **D)** $9s + 240n$
3s + 80n
math
102
Given that $\sin\alpha = \frac{3}{5}$, evaluate $\cos(\pi - 2\alpha)$.
-\frac{7}{25}
math
27
In triangle \(A B C, A B=6, B C=7\) and \(C A=8\). Let \(D, E, F\) be the midpoints of sides \(B C\), \(A C, A B\), respectively. Also let \(O_{A}, O_{B}, O_{C}\) be the circumcenters of triangles \(A F D, B D E\), and \(C E F\), respectively. Find the area of triangle \(O_{A} O_{B} O_{C}\).
\frac{21 \sqrt{15}}{16}
math
114
Acute-angled triangle $\triangle ABC$ is inscribed in a circle with center at $O$; $\stackrel \frown {AB} = 150^\circ$ and $\stackrel \frown {BC} = 60^\circ$. A point $E$ is chosen on the minor arc $AC$ of the circle such that $OE$ is perpendicular to $AC$. Determine the ratio of the magnitudes of $\angle OBE$ to $\ang...
2
math
104
Given the hyperbola $\dfrac{x^2}{a^2} - \dfrac{y^2}{b^2} = 1$ ($a > 0, b > 0$) has an asymptote $y = \sqrt{5}x$, calculate the eccentricity of the hyperbola.
\sqrt{6}
math
69
The doctor has told Cal O'Ree that during his ten weeks of working out at the gym, he can expect each week's weight loss to be $1\%$ of his weight at the end of the previous week. His weight at the beginning of the workouts is $244$ pounds. How many pounds does he expect to weigh at the end of the ten weeks? Express yo...
221
math
87
A top hat contains 5 red chips and 3 green chips. Chips are drawn randomly, one at a time without replacement, until either all 5 of the reds are drawn or all 3 green chips are drawn. Determine the probability that the 5 red chips are drawn before all 3 green chips are drawn.
\frac{3}{8}
math
66
In the arithmetic sequence $\left\{ {{a}_{n}} \right\}$, ${{a}_{1}}=-2,{{a}_{12}}=20$. (1) Find the general term (${{a}_{n}}$) of the sequence; (2) If ${{b}_{n}}=\frac{{{a}_{1}}+{{a}_{2}}+...+{{a}_{n}}}{n}$, find the sum of the first $n$ terms of the sequence $\left\{ {{3}^{{{b}_{n}}}} \right\}$.
\frac{{3}^{n}-1}{18}
math
124
Given that $\sin(\frac{\pi}{4} - \alpha) = \frac{1}{3}$, find the value of $\cos(\frac{\pi}{4} + \alpha)$.
\frac{1}{3}
math
42
What is the greatest possible common divisor of the numbers \(9m + 7n\) and \(3m + 2n\) if the numbers \(m\) and \(n\) have no common divisors other than one?
3
math
46
Given circle $O$: $x^{2}+y^{2}=1$ and point $A(-2,0)$, if point $B(b,0)$ ($b \neq -2$) and constant $\lambda$ satisfy: for any point $M$ on circle $O$, $|MB|=\lambda|MA|$, then: (I) $b=$ \_\_\_\_\_\_; (II) $\lambda=$ \_\_\_\_\_\_.
\frac{1}{2}
math
99
Given $m>0$ and $|x+1|+|2x-1|\geq m$ always holds, $a, b, c \in \mathbb{R}$ satisfy $a^2+2b^2+3c^2=m$. Find the minimum value of $a+2b+3c$.
-3
math
72
Let \( ABC \) be an isosceles triangle with \( AB = AC \). Let \( D \) and \( E \) be the midpoints of segments \( AB \) and \( AC \), respectively. Suppose that there exists a point \( F \) on ray \( \overrightarrow{DE} \) outside of \( ABC \) such that triangle \( BFA \) is similar to triangle \( ABC \). Compute \( \...
\sqrt{2}
math
100
Let $n$ be an odd integer with exactly 12 positive divisors. Find the number of positive divisors of $27n^3$.
256
math
32
For a positive integer \( n \), let \( S_{n} \) be the minimum value of \( \sum_{k=1}^{n} \sqrt{(2k-1)^{2} + a_{k}^{2}} \), where \( a_{1}, a_{2}, \cdots, a_{n} \) are positive real numbers whose sum is 17. There exists a unique \( n \) such that \( S_{n} \) is also an integer. Find \( n \).
12
math
112
What is the smallest whole number $b$ such that 62 can be expressed in base $b$ using only three digits?
4
math
27
There are two types of products, A and B, with profits of $p$ ten-thousand yuan and $q$ ten-thousand yuan, respectively. Their relationship with the invested capital $x$ ten-thousand yuan is: $p= \frac{1}{5}x$, $q= \frac{3}{5} \sqrt{x}$. Now, with an investment of 3 ten-thousand yuan in managing these two products, how...
\frac{21}{20}
math
114
Calculate the number of distinct three-digit numbers that can be formed using the digits 1, 2, 3, and 4.
64
math
28
<u>Set 1</u>**1.1** Compute the number of real numbers x such that the sequence $x$ , $x^2$ , $x^3$ , $ x^4$ , $x^5$ , $...$ eventually repeats. (To be clear, we say a sequence “eventually repeats” if there is some block of consecutive digits that repeats past some point—for instance, the sequence $1$ , $2$ , ...
9
math
388
A line is parameterized by a parameter $t,$ such that the vector on the line at $t = 1$ is $\begin{pmatrix} 2 \\ 5 \\ 7 \end{pmatrix},$ and the vector on the line at $t = 4$ is $\begin{pmatrix} 8 \\ -7 \\ 1 \end{pmatrix}.$ Find the vector on the line at $t = 0.$
\begin{pmatrix} 0 \\ 9 \\ 9 \end{pmatrix}
math
95
There are five volunteers, including A and B, who are assigned to serve at different positions in the China Pavilion, the UK Pavilion, the Australia Pavilion, and the Russia Pavilion at the Shanghai World Expo. Each position must be staffed by at least one volunteer. How many ways are there for A and B to each independ...
72
math
76
Find the greatest common divisor of $7524$ and $16083$.
1
math
20
What is the average number of pairs of consecutive integers in a randomly selected subset of $5$ distinct integers chosen from the set $\{ 1, 2, 3, …, 30\}$?
\frac{2}{3}
math
44
In the Cartesian coordinate system $xOy$, the parametric equation of curve $C$ is $\begin{cases}x=2\cos \alpha \\ y=2+2\sin \alpha\end{cases}$ (where $\alpha$ is the parameter), and the parametric equation of line $l$ is $\begin{cases}x= \sqrt{3}- \dfrac{ \sqrt{3}}{2}t \\ y=3+ \dfrac{1}{2}t\end{cases}$ (where $t$ is th...
2 \sqrt{3}
math
258
Find the largest constant $m$, so that for any positive real numbers $a, b, c, d,$ and $e$, \[\sqrt{\frac{a}{b+c+d+e}} + \sqrt{\frac{b}{a+c+d+e}} + \sqrt{\frac{c}{a+b+d+e}} + \sqrt{\frac{d}{a+b+c+e}} > m.\]
2
math
88
The quadratic \(x^2 + 2600x + 2600\) can be written in the form \((x+d)^2 + e\), where \(d\) and \(e\) are constants. What is \(\frac{e}{d}\)?
-1298
math
58
If the 200th day of some year is a Sunday and the 100th day of the following year is also a Sunday, what day of the week was the 300th day of the previous year? Provide the answer as the number of the day of the week (if Monday, then 1; if Tuesday, then 2, etc.).
1
math
78
In $\triangle{ABC}$, $AB = 10$, $\angle{A} = 45^\circ$, and $\angle{C} = 30^\circ$. Let $H, D,$ and $M$ be points on line $BC$ such that $AH \perp BC$, $\angle{BAD} = \angle{CAD}$, and $BM = CM$. Point $N$ is the midpoint of segment $HM$, and point $P$ is on ray $AD$ such that $PN \perp BC$. Find $AP^2$.
50
math
121
Given that a coin is tossed 9 times and lands heads up each time, calculate the probability that it lands heads up on the 10th toss.
\frac{1}{2}
math
32
Find the largest positive integer \( n \) such that \[\sin^n x + \cos^n x \ge \frac{1}{2n}\] for all real numbers \( x \).
8
math
41
Given the expression $(a+b+c+d+e+f+g+h+i)^{2}$, determine the number of different terms in the final answer after expansion and simplification.
45
math
36
Let's define strange numbers in the following way: A single-digit prime number is considered strange. A prime number with at least two digits is considered strange if, by removing either its first or last digit, the resulting number is also a strange number. Determine all the strange numbers.
2, \quad 3, \quad 5, \quad 7, \quad 23, \quad 37, \quad 53, \quad 73, \quad 373
math
56
In the era of "Internet$+$", there is a method of producing passwords using the "factorization method": factorizing a polynomial. For example, factorizing the polynomial $x^{3}-x$ results in $x\left(x+1\right)\left(x-1\right)$. When $x=20$, $x-1=19$, $x+1=21$, we can obtain the numerical password $201921$, or $192021$....
m=11; \ n=6
math
177
A 5x5 square is divided into 25 cells, all initially white. Neighbouring cells share a common edge. On each move, the colors of two neighbouring cells are changed to the opposite color (white cells become black and black ones become white). What is the minimum number of moves required to obtain a chess-like colouring? ...
12
math
102
Given an arithmetic sequence $\{a\_n\}$, the sum of its first $n$ terms, $S\_n$, satisfies $S\_3=0$ and $S\_5=-5$. The sum of the first 2016 terms of the sequence $\{ \frac{1}{a_{2n-1}a_{2n+1}} \}$ is $\_\_\_\_\_\_\_\_.$
-\frac{2016}{4031}
math
91
Let $A = (10,0,0),$ $B = (0,-6,0),$ $C = (0,0,8),$ and $D = (0,0,0).$ Find the point $P$ such that \[AP = BP = CP = DP.\]
(5, -3, 4)
math
63
The public security traffic police departments at all levels in Yunfu City remind citizens that they must strictly abide by the regulations of "one helmet per person" when riding a bike. A certain shopping mall in Yunan County simultaneously purchased two types of helmets, $A$ and $B$. It is known that purchasing $3$ t...
2048
math
277
Let $d(m)$ denote the number of positive integers that divide $m$, including $1$ and $m$. Define the function $g(m)=\frac{d(m)}{\sqrt[4]{m}}$. Find the unique positive integer $M$ such that $g(M) < g(m)$ for all positive integers $m \ne M$, and calculate the product of the digits of $M$.
2
math
84
Solve the problem where the equation $\sin^2 x + \sin^2 3x + \sin^2 5x + \sin^2 7x = 2$ must be reduced to the equivalent equation $\cos ax \cos bx \cos cx = 0$ for some positive integers $a,$ $b,$ and $c.$ Find $a + b + c.$
14
math
82
In the plane Cartesian coordinate system $xOy$, the parametric equations of curve $C_{1}$ are $\left\{\begin{array}{l}{x=1+\frac{\sqrt{3}t}{2},}\\{y=\frac{t}{2}}\end{array}\right.$ (where $t$ is the parameter). Using the origin $O$ as the pole and the positive half-axis of the $x$-axis as the polar axis, the polar coor...
|PA| \cdot |PB| = 1
math
200
Consider the polynomial \[P(z) = z^4 + 2z^3 + 6z^2 + 8z + 16\] having roots $w_1, w_2, w_3, w_4$. If $g(z) = -2\overline{z}$ transforms each root of $P(z)$ to generate a new polynomial \[Q(z) = z^4 + A'z^3 + B'z^2 + C'z + D'\] where $A', B', C', D'$ are complex numbers. Find the sum $B' + D'$. A) $40$ B) $104$ C) $280$...
280
math
160
Suppose that 1 euro is now worth 1.5 dollars. Diana has 600 dollars and Etienne has 350 euros. Additionally, there is a transaction fee of 2% when converting euros to dollars. Calculate the percent by which the value of Etienne's money is greater than or less than the value of Diana's money after accounting for the con...
14.25\%
math
80
Find the maximum value of the expression \( |\ldots|\left|x_{1}-x_{2}\right|-x_{3}|\ldots-x_{1990}\right| \), where \( x_{1}, x_{2}, \ldots, x_{1990} \) are distinct natural numbers from 1 to 1990.
1989
math
78
Given that the common ratio of the geometric sequence $\{a_{n}\}$ is $-\sqrt{2}$, find the value of $\ln (a_{2017})^{2}-\ln (a_{2016})^{2}=\_\_\_\_\_\_\_$.
\ln 2
math
63
If $f(x)$ is an odd function, increasing on $(0,+\infty)$, and $f(-3)=0$, solve the inequality $x \cdot f(x) < 0$.
(-3,0) \cup (0,3)
math
42
Given a circle C that passes through the three intersection points of the parabola $y=x^2-4x+3$ and the coordinate axes. (1) Find the equation of circle C; (2) Suppose the line $2x-y+2=0$ intersects circle C at points A and B, find $|AB|$.
\frac{6\sqrt{5}}{5}
math
73
Juliana wants to assign each of the 26 letters $A, B, C, D, \ldots, W, X, Y, Z$ of the alphabet a nonzero numerical value, such that $A \times C = B, B \times D = C, C \times E = D$, and so on, up to $X \times Z = Y$. a) If Juliana assigns the values 5 and 7 to $A$ and $B$ respectively, what will be the values of $C,...
2010
math
212
Given the fraction $\frac{x-2}{x+1}$, determine the value of $x$ for which the fraction is undefined.
-1
math
28
The number $\sqrt{104\sqrt{6}+468\sqrt{10}+144\sqrt{15}+2006}$ can be written as $a\sqrt{2}+b\sqrt{3}+c\sqrt{5},$ where $a, b,$ and $c$ are positive integers. Find $abc$.
936
math
83
Definition: If the two real roots of a quadratic equation in $x$, $ax^{2}+bx+c=0 (a\neq 0)$, are $x_{1}$ and $x_{2} (x_{1}\leqslant x_{2})$, and the point $M(x_{1}, x_{2})$ is plotted with $x_{1}$ and $x_{2}$ as the coordinates, then point $M$ is called the derived point of the quadratic equation.<br/>$(1)$ If the equa...
\frac{1}{2}
math
192
Let $\{a_{n}\}$ be an arithmetic sequence with a common difference of $d$, and $\{b_{n}\}$ be a geometric sequence with a common ratio of $q$. Given $a_{1}=b_{1}=1$, $b_{4}=64$, and $q=2d$. $(1)$ Find the general term formulas for sequences $\{a_{n}\}$ and $\{b_{n}\}$. $(2)$ Let $c_{n}=a_{2n-1}+b_{2n}$. Find the su...
2n^{2} - n + \frac{4^{2n+1} - 4}{15}
math
147
Four distinct points are arranged on a plane such that they have segments connecting them with lengths $a$, $a$, $a$, $b$, $b$, and $2a$. Determine the ratio $\frac{b}{a}$ assuming the formation of a non-degenerate triangle with one of the side lengths being $2a$.
\sqrt{2}
math
67
A box contains $6$ balls, of which $3$ are yellow, $2$ are blue, and $1$ is red. Three balls are drawn from the box. $(1)$ If the $3$ yellow balls are numbered as $A$, $B$, $C$, the $2$ blue balls are numbered as $d$, $e$, and the $1$ red ball is numbered as $x$, use $(a,b,c)$ to represent the basic event. List all th...
\frac{4}{5}
math
137
The base of a pyramid is a rectangle with an area of \( S \). Two of the lateral faces are perpendicular to the base, and the other two are inclined at angles of \( 30^{\circ} \) and \( 60^{\circ} \) to the base. Find the volume of the pyramid.
\frac{S \sqrt{S}}{3}
math
68
Given the functions $f(x) = \ln x$, $g(x) = \frac{1}{2}x^2 - 2x$, for $x > 2$, if $k(x - 2) < xf(x) + 2g'(x) + 3$ always holds, the maximum integer value of $k$ is ____.
k = 5
math
76
Given vectors $\overrightarrow{m} =\left(\begin{matrix} \sqrt{3}\sin \frac{x}{4},1 \end{matrix}\right)$, $\overrightarrow{n} =\left(\begin{matrix}\cos \frac{x}{4},\cos ^{2} \frac{x}{4} \end{matrix}\right)$. $(1)$ If $\overrightarrow{m} \perp \overrightarrow{n}$, find the value of $\cos \left(\begin{matrix} \frac{2\pi}...
\left(1, \frac{3}{2} \right)
math
205
A fair standard six-sided dice is tossed four times. Given that the sum of the first three tosses equals the fourth toss, what is the probability that at least one "3" is tossed? A) $\frac{1}{6}$ B) $\frac{6}{17}$ C) $\frac{9}{17}$ D) $\frac{1}{2}$ E) $\frac{1}{3}$
\frac{9}{17}
math
91
A certain three-digit number is a multiple of 2. Adding 1 to it results in a multiple of 3. Adding 2 to it results in a multiple of 4. Adding 3 to it results in a multiple of 5. Adding 4 to it results in a multiple of 6. What is the smallest such number?
122
math
71
In triangle $\triangle ABC$, the lengths of the sides opposite angles $A$, $B$, and $C$ are $a$, $b$, and $c$ respectively. Given that $A=\frac{{2π}}{3}$, $a=4$, $D$ is the midpoint of $BC$, and $AD=\sqrt{2}$, find the perimeter of $\triangle ABC$.
4+2\sqrt{5}
math
82
In a set of data $0$, $3$, $5$, $7$, $10$, adding an integer $a$ to form a new set of data. The new set of data has an average that is not greater than the original data and a smaller variance. One possible value of $a$ is ____.
2
math
66
Given the equation of the line $3x+2y-1=0$, find one of its directional vectors.
(2,-3)
math
24
In $\triangle ABC$, let the sides opposite to angles $A$, $B$, and $C$ be $a$, $b$, and $c$, respectively, and $\frac{\cos C}{\cos B} = \frac{3a-c}{b}$. (1) Find the value of $\sin B$; (2) If $b = 4\sqrt{2}$ and $a = c$, find the area of $\triangle ABC$.
8\sqrt{2}
math
96
A cuckoo clock chimes "cuckoo" as many times as the hour indicated by the hour hand (e.g., at 19:00, it chimes 7 times). One morning, Maxim approached the clock at 9:05 and started turning the minute hand until the clock advanced by 7 hours. How many times did the clock chime "cuckoo" during this period?
43
math
86
Find the number of ordered pairs $(x,y)$ of real numbers such that \[9^{x^2 + y} + 9^{x + y^2} = 1.\]
1
math
40
The Lopez family has grown and now includes three children. They still travel in their family car that has a driver's seat, a front passenger seat, and three seats in the back. Either Mr. Lopez, Mrs. Lopez, or their eldest child must sit in the driver's seat. How many different seating arrangements are possible now?
72
math
67
Given the function $f(x)=\begin{cases} & e^{x},x\geqslant 0 \\ & -x^{3},x < 0 \\ \end{cases}$, if $g(x)=f(f(x))-a(a > 0)$ has two distinct zeros $(x_{1})$, $(x_{2})$, calculate the maximum value of $(e^{x_{1}}\cdot e^{x_{2}})$.
\frac{27}{e^{3}}
math
96
Given a randomly selected number $x$ in the interval $[0,\pi]$, determine the probability of the event "$-1 \leqslant \tan x \leqslant \sqrt {3}$".
\dfrac{7}{12}
math
46
If the radius of the top base of a truncated cone is $5$, the radius of the bottom base is $R$, and a section (a plane parallel to the top and bottom bases and equidistant from them) divides the truncated cone into two parts with a ratio of side areas of $1:2$, then $R=\_\_\_\_\_\_.$
25
math
75
Given the parabola $C$: $y^{2}=4x$ with focus $F$ and a point $P(1,m)$ on parabola $C$. (1) If the ellipse $C'$: $\frac{x^{2}}{4}+ \frac{y^{2}}{n}=1$ shares a common focus with the parabola $C$, find the equation of ellipse $C'$. (2) Let $A$ and $B$ be the intersection points of the parabola $C$ and the ellipse $C'$ fo...
3x^{2}- \frac{y^{2}}{2}=1
math
159
Determine the domain of $f(x+1)$, where $f(x) = \frac{1}{\sqrt{\log_{\frac{1}{2}}(2x-1)}}$.
\left(-\frac{1}{2}, 0\right)
math
42
Given that the area of an equilateral triangle $ABC$ is 1, and $P$ is a point inside $\triangle ABC$, with the areas of $\triangle PAB$, $\triangle PBC$, and $\triangle PCA$ being equal, then the total number of points $P$ that satisfy the condition is $\boxed{1}$; the area of $\triangle PAB$ is $\boxed{\frac{1}{3}}$.
\frac{1}{3}
math
89
Count the number of positive even multiples of $5$ less than $3000$ that are perfect squares.
5
math
24
There are four balls in a bag, each with the same shape and size, and their numbers are \\(1\\), \\(2\\), \\(3\\), and \\(4\\). \\((1)\\) Draw two balls randomly from the bag. Calculate the probability that the sum of the numbers on the balls drawn is no greater than \\(4\\). \\((2)\\) First, draw a ball randomly fro...
\dfrac{13}{16}
math
139
Given that \(x^{2} + y^{2} = 25\), find the maximum value of the function \(z = \sqrt{8y - 6x + 50} + \sqrt{8y + 6x + 50}\).
6\sqrt{10}
math
58