1-cos^2(A)cos^2(B)+sin^2(A)sin^2(B)求化简
问题描述:
1-cos^2(A)cos^2(B)+sin^2(A)sin^2(B)求化简
AB是数
答
1-cos^2(A)cos^2(B)+sin^2(A)sin^2(B)=1+(sinAsinB+cosAcosB)(sinAsinB-cosAcosB)
=1-cos(A-B)cos(A+B)