syms x1 x2 p a
x1=input('请输入x1的值')
x2=input('请输入x2的值')
a=x1+x2
switch 1
    case a>1
        p = 0.5457*exp(-0.75*x2^2-3.75*x1^2-1.5*x1)
    case -1<a & a<=1
        p = 0.7575*exp(-x2^2-6*x1^2)
    case a<=-1
        p = 0.5457*exp(-0.75*x2^2-3.75*x1^2+1.5*x1)
end