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int64
5
895
The length of the shortest trip from $A$ to $C$ along the edges of a cube shown is the length of 4 edges. How many different 4-edge trips are there from $A$ to $C$? [asy] size(4cm,4cm); pair a1, b1, c1, d1; a1=(1,1); b1=(0,1); c1=(1.6,1.4); d1=(1,0); pair e1, f1, g1, h1; e1=(0,0); f1=c1-(a1-d1); g1=b1+(c1-a1); h1=e1+(...
12
math
240
In rectangle $ABCD$, the diagonals intersect at point $O$. If $AB = 12$ and $BC = 16$, what is $\sin \angle BAO$?
0.6
math
41
Given the function $f(x)=2|x|+|2x-m|$ where $m>0$, and the graph of the function is symmetric about the line $x=1$. $(Ⅰ)$ Find the minimum value of $f(x)$. $(Ⅱ)$ Let $a$ and $b$ be positive numbers such that $a+b=m$. Find the minimum value of $\frac{1}{a}+\frac{4}{b}$.
\frac{9}{4}
math
96
Given the function f(x) = e^x + ae^-x, where 'a' is a constant. If f(x) is an odd function, find the value of 'a'. If f(x) is an increasing function on R, find the range of 'a'.
a \in (-\infty, 0]
math
57
The center of a circle is on the positive half of the $x$-axis, and its radius is the length of the imaginary semi-axis of the hyperbola $\dfrac{x^{2}}{16} - \dfrac{y^{2}}{9} = 1$, and it is tangent to the asymptotes of this hyperbola. The equation of the circle is __________.
(x-5)^{2} + y^{2} = 9
math
84
Given that the elevation angle of point B in the same direction as observed from point A is 60^{\circ}, and the depression angle of point C is 70^{\circ}, find the measure of angle ∠BAC.
130^{\circ}
math
50
Given \(\frac{1+\sin x}{\cos x}=\frac{22}{7}\), and \(\frac{1+\cos x}{\sin x}=\frac{m}{n}\) (where \(\frac{m}{n}\) is in simplest form). Find \(m+n\).
44
math
67
A geometric sequence contains $5$ terms, each of which is a positive integer less than $100$, and the sum of these $5$ terms is $121$. Find the sum of the terms in odd positions of the sequence.
91
math
51
Given two sets $A=\{x \mid 1 < x - 1 < 3\}$ and $B=\{x \mid (x - 3)(x - a) < 0\}$, 1. When $a=5$, find $A \cap B$ and $A \cup B$. 2. If $A \cap B = B$, find the range of the real number $a$.
[2, 4]
math
90
If the power function $f(x) = x^{k}$ is a decreasing function on $(0, +\infty)$, determine the value of $k$.
-1
math
34
For the complex number $z=\frac{3+i}{1-2i}$ (where $i$ is the imaginary unit), find $|\overline{z}|$.
\sqrt{2}
math
36
$2019$ students are voting on the distribution of $N$ items. For each item, each student submits a vote on who should receive that item, and the person with the most votes receives the item (in case of a tie, no one gets the item). Suppose that no student votes for the same person twice. Compute the maximum possibl...
1009
math
100
What is the minimum value of the expression $x^2 + y^2 - 8x + 6y + 20$ for real $x$ and $y$?
-5
math
39
Given that $x$ is the arithmetic mean between 4 and 16, find the value of $x$.
10
math
24
Consider the parabola $C$: $y^{2}=4x$ with focus $F$. The line $l$ passing through $F$ intersects $C$ at points $A$ and $B$. Given point $M(-1,2)$, if $\overrightarrow{MA} \cdot \overrightarrow{MB}=0$, then the slope of line $l$ is $k=$\_\_\_\_\_\_.
k=1
math
90
In triangle \(ABC\) with a \(120^\circ\) angle at vertex \(A\), the bisectors \(AA_1\), \(BB_1\), and \(CC_1\) are drawn. Find the angle \(C_1 A_1 B_1\).
90^\circ
math
60
In a box, there are 6 ballpoint pens: 3 are black, 2 are blue, and 1 is red. Three pens are randomly selected from the box. (1) How many basic events are there in this experiment? If the 3 black ballpoint pens are labeled as A, B, C, the 2 blue ballpoint pens as d, e, and the 1 red ballpoint pen as x, and a basic eve...
\frac{4}{5}
math
146
Triangle $ABC$ has sides tangent to a circle with center $O$. Given that $\angle ABC = 72^\circ$ and $\angle BAC = 67^\circ$, find $\angle BOC$, where the circle is the excircle opposite vertex $C$.
110.5^\circ
math
57
The graph of the function $y=\sin x$ is translated according to the vector $\overrightarrow{a}=(-\frac{\pi}{2}, 2)$ and then coincides with the graph of the function $g(x)$. Determine the function $g(x)$.
\cos x+2
math
57
1. Given $\tan \frac{\alpha}{2} = \frac{1}{2}$, find the value of $\sin\left(\alpha + \frac{\pi}{6}\right)$. 2. Given $\alpha \in \left(\pi, \frac{3\pi}{2}\right)$ and $\cos\alpha = -\frac{5}{13}$, $\tan \frac{\beta}{2} = \frac{1}{3}$, find the value of $\cos\left(\frac{\alpha}{2} + \beta\right)$.
-\frac{17\sqrt{13}}{65}
math
121
In a positive geometric sequence $\{a_n\}$, it is known that $a_1a_2a_3=4$, $a_4a_5a_6=12$, and $a_{n-1}a_na_{n+1}=324$. Determine the value of $n$.
14
math
69
Given the function $y=\cos \left(2x-\frac{\pi }{6}\right)$, determine the horizontal shift required to obtain the graph of the function $y=\sin \left(2x+\frac{\pi }{6}\right)$.
\frac{\pi }{12}
math
55
If ${x^2}+x=5+\sqrt{5}$, then the value of $x$ is ____.
\sqrt{5} \text{ or } -\sqrt{5} - 1
math
26
Find all positive integers $k$ , so that there exists a polynomial $f(x)$ with rational coefficients, such that for all sufficiently large $n$ , $$ f(n)=\text{lcm}(n+1, n+2, \ldots, n+k). $$
k = 1
math
62
Let $x,$ $y,$ and $z$ be positive real numbers. Find the minimum value of \[\frac{4z}{2x + y} + \frac{4x}{y + 2z} + \frac{y}{x + z}.\]
3
math
60
Given \(\vec{O}P = (2,1)\), \(\vec{O}A = (1,7)\), and \(\vec{O}B = (5,1)\), let \(X\) be a point on the line \(OP\) (with \(O\) as the coordinate origin). Find the measure of the angle \(\angle AXB\) when the dot product \(\vec{X}A \cdot \vec{X}B\) is minimized.
\arccos\left(-\frac{4 \sqrt{17}}{17}\right)
math
102
In the Cartesian coordinate system \( xOy \), the function \( f(x) = a \sin(ax) + \cos(ax) \) (where \( a > 0 \)) is defined. Find the area of the closed region formed by the graph of \( f(x) \) over its smallest positive period and the graph of \( g(x) = \sqrt{a^2 + 1} \).
\frac{2 \pi}{a} \sqrt{a^{2}+1}
math
86
A point $P$ is chosen uniformly at random inside a square of side length 2. If $P_{1}, P_{2}, P_{3}$, and $P_{4}$ are the reflections of $P$ over each of the four sides of the square, find the expected value of the area of quadrilateral $P_{1} P_{2} P_{3} P_{4}$.
8
math
85
Among the rational numbers $\left(-1\right)^{2}$, $\left(-1\right)^{3}$, $-1^{2}$, $|-1|$, $-\left(-1\right)$, $\frac{1}{{-1}}$, determine the number of them that equals 1.
3
math
67
Given the function $f(x)=\ln (x+1)- \frac{ax}{x+1}-x$, where $a\in R$. (I) Find the monotonic intervals of the function $f(x)$ when $a > 0$. (II) If there exists $x > 0$ such that $f(x)+x+1 < - \frac{x}{x+1}$ ($a\in Z$) holds, find the minimum value of $a$.
5
math
103
In the sequence $\{a_{n}\}$, $a_{1}=18$, $a_{2}=24$, $a_{n+2}-a_{n}=-6$. $(1)$ Find the general formula for $\{a_{n}\}$; $(2)$ Let the sum of the first $n$ terms of the sequence $\{a_{n}\}$ be $S_{n}$, find the maximum value of $S_{n}$.
96
math
100
In $\triangle ABC$, the sides opposite to angles $A$, $B$, and $C$ are denoted as $a$, $b$, and $c$ respectively. $(1)$ If $\cos \left(A+ \frac {\pi}{6}\right)=\sin A$, find the value of $A$; $(2)$ If $\cos A= \frac {1}{4}$ and $4b=c$, find the value of $\sin B$.
\frac {1}{4}
math
98
What is the smallest positive integer $n$ such that $23n \equiv 5678 \pmod{11}$?
2
math
30
In the arithmetic sequence $\{a_n\}$, if $a_1 + a_4 + a_7 = 39$ and $a_2 + a_5 + a_8 = 33$, calculate the value of $a_3 + a_6 + a_9$.
27
math
64
What is the minimum value of the expression $2x^2+3y^2+8x-24y+62$ for real $x$ and $y$?
6
math
39
Given the function $f(x) = ax - \ln x$, if $f(x) > 1$ always holds true in the interval $(1, +\infty)$, determine the range of the real number $a$.
[1, +\infty)
math
48
A traffic light cycles as follows: green for 45 seconds, then yellow for 5 seconds, and then red for 50 seconds. Mark chooses a random five-second interval to observe the light. What is the probability that the color changes during his observation?
\frac{3}{20}
math
54
From a square with a side length of 5, four corner unit squares are cut out (see figure). What is the area of the largest square that can be cut out from the remaining part?
9
math
40
Given that a line passes through points $A(1,3)$ and $B(2,5)$, calculate the slope of this line.
2
math
30
A store increased the original price of a product by $20\%$ and then decreased the new price by $x\%$. The final price turned out to be $88\%$ of the original price. Find the value of $x$.
26.67
math
53
Given the non-negative real numbers $x$ and $y$ that satisfy the constraints: $$ \begin{cases} x+y-3 \leq 0 \\ 2x+y-4 \geq 0 \end{cases} $$ find the maximum value of $z=2x+3y$.
8
math
67
In $\triangle ABC$, the sides opposite to angles $A$, $B$, and $C$ are denoted as $a$, $b$, and $c$ respectively, with $C= \frac{\pi}{3}$, $b=8$, and the area of $\triangle ABC$ is $10\sqrt{3}$. $(1).$ Find the value of $c$; $(2).$ Find the value of $\cos(B-C)$.
\frac{13}{14}
math
97
Given that the radius of the circumcircle of acute triangle ABC is $\frac{\sqrt{3}}{3}BC$, and $AB = 3$, $AC = 4$, find the length of $BC$.
\sqrt{13}
math
45
A rectangular park is one-third as wide as it is long, and it is completely enclosed by 90 meters of fencing. What is the number of square meters in the area of the park?
379.6875
math
40
Given a sequence $\{a_{n}\}$ where $a_{1}=1$, and $\left(n+1\right)a_{n+1}-na_{n}=2n+1$, if $b_{n}=[\lg a_{n}]$, and the sum of the first $n$ terms of the sequence $\{b_{n}\}$ is $T_{n}$, calculate $T_{2022}$.
4959
math
92
Given $\sin(\alpha - \beta) = \frac{1}{3}$ and $\cos \alpha \sin \beta = \frac{1}{6}$, find $\cos(2\alpha + 2\beta)$.
\frac{1}{9}
math
49
Let $a,$ $b,$ $c$ be positive real numbers such that $a + b + c = 1.$ Find the minimum value of $a^2 + 2b^2 + c^2.$
\frac{2}{5}
math
47
Let \[f(x) = \left\{ \begin{array}{cl} x^2 - 4 &\text{ if }x>6, \\ 3x + 2 &\text{ if } -6 \le x \le 6, \\ 5 &\text{ if } x < -6. \end{array} \right.\] If \( x \) is a multiple of 3, add 5 to \( f(x) \). Find \( f(-8) + f(0) + f(9) \).
94
math
118
Let's consider a modified version of Lucas numbers defined by the recursion $M_0 = 3, M_1 = 2$, and subsequently $M_n = M_{n-1} + M_{n-2}$. Compute the units digit of $M_{M_{12}}$.
1
math
62
The arithmetic sequence $\{a_{n}\}$ has a first term $a_{1}=1$, a common difference $d \neq 0$, and satisfies the condition $a_{3} \cdot a_{4} = a_{12}$. (1) Find the general term formula for the sequence $\{a_{n}\}$; (2) Let $b_{n} = a_{n} \cdot 2^{n}$, find the sum of the first $n$ terms, $T_{n}$, for the sequence $\...
T_{n} = (n-1) \cdot 2^{n+1} + 2
math
123
In Weather Town, the forecast predicts a 75% chance of rain each day during the upcoming five-day festival. On days it doesn’t rain, the weather will be sunny. Jasmine and Lee hope for exactly two sunny days during this time, as they plan indoor activities otherwise. What is the probability they get the weather they wa...
\frac{135}{512}
math
75
Determine the range of the function $f(x) = \left(\frac{1}{4}\right)^x - 3\left(\frac{1}{2}\right)^x + 2$ where $x \in [-2, 2]$.
[-\frac{1}{4}, 6]
math
55
Complex numbers $a$, $b$, $c$ form an equilateral triangle with side length 24 in the complex plane. If $|a + b + c| = 48$, find $|ab + ac + bc|$.
768
math
51
Jonas sets his watch correctly at 8:00 AM and notices that his watch reads 9:48 AM at the actual time of 10:00 AM. Assuming his watch loses time at a constant rate, calculate the actual time when his watch will first read 5:00 PM.
6:00 PM
math
65
Given the function $f(x)=\log_{2}(1-x)-\log_{2}(1+x)$. (1) Find the domain of the function $f(x)$; (2) Determine the parity (odd or even) of $f(x)$; (3) Does the equation $f(x)=x+1$ have any roots? If it does have a root $x_{0}$, find an interval $(a,b)$ with a length of $\frac{1}{4}$ such that $x_{0}\in(a,b)$; otherwi...
\left(-\frac{1}{2},-\frac{1}{4}\right)
math
139
Calculate the arc length of the curve described by the equation in the rectangular coordinate system. $$ y = \ln \left(1-x^{2}\right), \quad 0 \leq x \leq \frac{1}{4} $$
\frac{1}{2} \ln \left( \frac{5}{3} \right) + \frac{1}{4}
math
52
Given that $C_{n+1}^{7} - C_{n}^{7} = C_{n}^{8}$, calculate the value of $n$.
14
math
36
Given the function $f(x) = x^2 + 1$, calculate the value of $f(a + 1)$.
a^{2}+2a+2
math
27
Solve the following system of equations: $$ \begin{array}{r} x^{2} + y \sqrt{x y} = 105 \\ y^{2} + x \sqrt{y x} = 70 \end{array} $$
(x, y) = (9, 4)
math
57
During the holiday, a school organizes a trip for 360 teachers and students. A bus rental company offers two types of buses for hire: Type A buses have 40 seats each and a rental fee of 400 yuan; Type B buses have 50 seats each and a rental fee of 480 yuan. The minimum rental fee required to hire buses from this compan...
3520
math
86
Let $b_1, b_2, \ldots$ be a sequence determined by the rule $b_n= \frac{b_{n-1}}{3}$ if $b_{n-1}$ is divisible by 3, and $b_n = 2b_{n-1} + 2$ if $b_{n-1}$ is not divisible by 3. Determine how many positive integers $b_1 \le 3000$ are such that $b_1$ is less than each of $b_2$, $b_3$, and $b_4$.
2000
math
129
Shea and Ara were the same height originally. Shea has grown by 25%, and Ara has grown by one-third the number of inches Shea has grown. If Shea is now 70 inches tall, calculate Ara's current height in inches.
60.67
math
51
In the polar coordinate system, given point A (2, $\frac{\pi}{2}$), and point B lying on the line $l: \rho \cos \theta + \rho \sin \theta = 0$ (where $0 \leq \theta \leq 2\pi$), find the polar coordinates of point B when the length of segment AB is the shortest.
(\sqrt{2}, \frac{3\pi}{4})
math
82
**A park is designed with two circular walking tracks. The smaller track has a diameter of 15 meters. If the diameter of the larger track is 20 meters, what percent increase in area results from the larger track compared to the smaller one?**
77.78\%
math
53
Let \( x \) and \( y \) be positive real numbers. Find the minimum value of \[ \frac{\sqrt{(x^2 + y^2)(4x^2 + y^2)}}{xy}. \]
3
math
50
In a certain sequence, the first term is $a_1 = 2010$ and the second term is $a_2 = 2011$. Furthermore, the values of the remaining terms are chosen so that $a_n + a_{n+1} + a_{n+2} = 2n$ for all $n \geq 1$. Determine $a_{1000}$.
2676
math
90
Determine the value of \( n \) such that \( 2^7 \cdot 3^4 \cdot n = 10! \).
350
math
32
Interior numbers begin in the third row of Pascal's Triangle. The sum of the interior numbers in the fourth row is 6. The sum of the interior numbers of the fifth row is 14. What is the sum of the interior numbers of the seventh row?
62
math
54
Given that the probability that each ball falls into bin k is 3^(-k) for k = 1,2,3,..., find the probability that the blue ball falls into a lower-numbered bin than the yellow ball.
\frac{7}{16}
math
48
Given that \(x\) is real and \(x^3 + \frac{1}{x^3} = 116\), find the value of \(x + \frac{1}{x}\).
4
math
44
Hexagon $ABCDEF$ has its center at $G$. Each vertex and the center are to be assigned one of the digits $1$ through $7$, with each digit used exactly once, such that the sums of the numbers on the lines $AGC$, $BGD$, and $CGE$ are all equal. How many ways can this be done?
144
math
75
Place water in air at a temperature of $\theta$℃ to cool it. If the original temperature of the water is $\theta_1$℃ ($\theta < \theta_1$), the temperature $\theta$℃ of the object after $t$ minutes can be obtained by the formula $\theta = \theta + (\theta_1 - \theta)e^{-kt}$, where $k$ is a positive constant determined...
22.8\,^\circ\text{C}
math
239
A bookshelf has $6$ different English books and $2$ different math books. If you randomly pick $1$ book, calculate the number of different ways to pick the book.
6 + 2 = 8
math
38
On the sides $AB$, $BC$, and $AC$ of triangle $ABC$, whose area is 75, points $M$, $N$, and $K$ are respectively located. It is known that $M$ is the midpoint of $AB$, the area of triangle $BMN$ is 15, and the area of triangle $AMK$ is 25. Find the area of triangle $CNK$.
15
math
91
If $B$ is an angle such that $\tan B - \sec B = -1,$ determine all possible values of $\cos B,$ separated by commas.
1
math
33
Solve the system of equations: $$ \begin{aligned} & \frac{1}{x} = y + z \\ & \frac{1}{y} = z + x \\ & \frac{1}{z} = x + y \end{aligned} $$
\left( \frac{\sqrt{2}}{2}, \frac{\sqrt{2}}{2}, \frac{\sqrt{2}}{2} \right), \left( -\frac{\sqrt{2}}{2}, -\frac{\sqrt{2}}{2}, -\frac{\sqrt{2}}{2} \right)
math
59
Given that the sum of the first $n$ terms of a geometric sequence $\{a_n\}$ is $S_n=(a-2)\cdot3^{n+1}+2$, find the constant $a$.
\dfrac {4}{3}
math
46
The opposite of the number $2023$ is $-2023$.
-2023
math
19
Let $f : \mathbb{R} \to \mathbb{R}$ be a function such that $f(1) = 2$ and \[f(x^2 + y^2) = (x + y) (f(x) - f(y))\]for all real numbers $x$ and $y$. Let $n$ be the number of possible values of $f(3),$ and let $s$ be the sum of all possible values of $f(3).$ Find $n \times s.$
6
math
114
Find the value of $s$ for which the vector \[\bold{u} = \begin{pmatrix} 1 \\ -2 \\ -4 \end{pmatrix} + s \begin{pmatrix} 5 \\ 3 \\ -2 \end{pmatrix}\] is closest to \[\bold{b} = \begin{pmatrix} 3 \\ 3 \\ 4 \end{pmatrix}.\]
\frac{9}{38}
math
95
Taxi driver Li Shifu's operation on the first afternoon of National Day was conducted on a north-south road. If heading south is denoted as "$-$" and heading north is denoted as "$+$", his driving situation that afternoon was as follows: (unit: kilometers, each trip with passengers $)-2,-3,-6,+8,-9,-7,-5,+13.$ $(1)$ W...
106.08 \text{ yuan}
math
303
Find \( n > 1 \) such that using stamp denominations of \( n \) and \( n+2 \), it is possible to obtain any value \( \geq 2n + 2 \).
3
math
45
An equilateral triangle is inscribed in a circle, then a circle is inscribed in this triangle, a square is then inscribed in this inner circle, and finally, a circle is inscribed in that square. What is the ratio of the area of the smallest circle to the area of the largest circle?
\frac{1}{8}
math
63
Given that the monotonically decreasing function $f(x)$ defined on $(-\infty, 3]$ satisfies $f(1+\sin ^{2}x)\leqslant f(a-2\cos x)$ for all real numbers $x$, determine the range of values for $a$.
(-\infty,-1]
math
64
Given a cuboid with length, width, and height as $2a$, $a$, and $a$ respectively, and all its vertices are on a sphere, calculate the surface area of the sphere.
6\pi a^2
math
42
Let point $C(0,p)$ lie on the $y$-axis and another point $D(x,0)$ lie on the $x$-axis, where $x$ and $p$ are positive integers with $D$ located between $O(0,0)$ and $B(12,0)$. Find an expression for the area of $\triangle COD$ in terms of $x$ and $p$.
\frac{xp}{2}
math
89
Using three-digit powers of $3$ and $7$ in a cross-number puzzle, determine the unique possible digit for the intersecting square.
3
math
29
First, find the derivative of the following functions and calculate the derivative at \\(x=\pi\\). \\((1) f(x)=(1+\sin x)(1-4x)\\)    \\((2) f(x)=\ln (x+1)-\dfrac{x}{x+1}\\).
\dfrac{\pi}{(\pi+1)^{2}}
math
66
For the inequality $kx^{2}-kx+4\geqslant 0$ to hold for any $x\in R$, the range of values for $k$ is ____.
[0,16]
math
42
Factor the following expressions: \\((1) 5x^{2}+6xy-8y^{2}\\) \\((2) x^{2}+2x-15-ax-5a\\)
(x+5)(x-3-a)
math
46
The common chord length of Circle \\(O_{1}\\): \\(x^{2}+y^{2}-2x=0\\) and Circle \\(O_{2}\\): \\(x^{2}+y^{2}-4y=0\\) is to be calculated.
\dfrac {4 \sqrt {5}}{5}
math
61
Given quadrilateral ABCD, there are four conditions: AB∥CD, AB=CD, BC∥AD, BC=AD. Determine the total number of ways to select two conditions from these that can make quadrilateral ABCD a parallelogram.
4
math
51
In the rectangular coordinate system $(xOy)$, the parametric equations of curve $C_1$ are given by $\begin{cases} x=2+2\cos{\varphi}, \\ y=2\sin{\varphi} \end{cases}$ where $\varphi$ is a parameter. Curve $C_2$ has a polar coordinate equation of $\rho =4\sin{\theta}$ with the origin $O$ as the pole and the positive hal...
\alpha = \frac{3\pi}{4}
math
259
Given a point M(2, 1), draw a line l that intersects the ellipse $\frac{x^2}{16} + \frac{y^2}{4} = 1$ at points A and B. If point M is the midpoint of segment AB, find the equation of line l.
x + 2y - 4 = 0
math
64
For vectors \(\mathbf{v} = \begin{pmatrix} 2 \\ 3 \end{pmatrix}\) and \(\mathbf{w} = \begin{pmatrix} -4 \\ 1 \end{pmatrix}\), compute \(\text{proj}_{\mathbf{w}} \mathbf{v}\).
\begin{pmatrix} \frac{20}{17} \\ -\frac{5}{17} \end{pmatrix}
math
75
Given the numbers \( x_{1}, \ldots, x_{n} \in \left(0, \frac{\pi}{2}\right) \), find the maximum value of the expression \[ A = \frac{\sin x_{1} + \ldots + \sin x_{n}}{\sqrt{\operatorname{tg}^{2} x_{1} + \ldots + \operatorname{tg}^{2} x_{n} + n}} \]
\frac{\sqrt{n}}{2}
math
104
In a plane, \( n \) lines are drawn such that each pair of lines intersects, but no four lines pass through a single point. There are a total of 16 intersection points, and 6 of these points are passed through by three lines. Find \( n \).
8
math
58
Find the length of the common chord of circle $C_{1}$: $x^{2}+y^{2}-9=0$ and circle $C_{2}$: $x^{2}+y^{2}-6x+8y+9=0$.
\frac{24}{5}
math
57
An ellipse has its foci at $(1, 1)$ and $(1, 3)$. Given that it passes through the point $(6, 2)$, its equation can be written in the form \[\frac{(x-h)^2}{a^2} + \frac{(y-k)^2}{b^2} = 1\] where $a, b, h, k$ are constants, and $a$ and $b$ are positive. Find $a+k.$
7
math
103
Express the production of new energy vehicles in China in 2022 (7,003,000) in scientific notation.
7.003 \times 10^{6}
math
30