设A=asin^2x+bcos^2x,B=acos^2x+bsin^2x(a、b、x∈R),则m=AB,n=ab,P=A^2+B^2,E=a^2+b^2满足?

问题描述:

设A=asin^2x+bcos^2x,B=acos^2x+bsin^2x(a、b、x∈R),则m=AB,n=ab,P=A^2+B^2,E=a^2+b^2满足?

P+2m=E+2n
提示:A+B=a+b