化简 sin^4a-cos^4b
化简 sin^4a-cos^4b
若sin^4a/sin^2b+cos^4a/cos^2b=1,证明sin^4b/sin^2a+cos^4b/cos^2a
sin(a)*cos(a)=4,那么sin(a) cos(b)=?
cos(a+b)+cos(a-b)/sin(a+b)+sin(a-b)化简
1-sin^6a-cos^6a分之1-sin^4a-cos^4a 化简
化简1-sin^4a-cos^4a/1-sin^6a-cos^6a
已知sin[a-b]cos a-cos[b-a]sin a=3/5,b是第三象限角,求sin[b+5π/4]的值
sin(a+B)cos(y-B)-cos(B+a)sin(B-y) 化简
化简 1-sin^4a-cos^4a/cos^2a-cos^4a
化简(1-sin^6 a-cos^6 a)/(cos^2 a-cos^4 a)==
a*sin(pi/4 - x) - b*cos(pi/4 - x) = a*sin(pi/4 + x) - b*cos(
已知向量a=(sin(A+B)/2,cos(A-B)/2-3根号2/4) 向量b=(5/4sin(A+B)/2,cos(