化简,4sin^2a(1-sin^2a)+cos^22a,

(1-sin^4a-cos^4)/(sin^2a-sin^4a) 化简 化简Sin A + Sin 2A / 1+cos A + cosA+cos^2A=1,sin^2A+sin^4A+sin^8A (1-sin^6a-cos^6a)/(sin^2a-sin^4a) sin^2(-a)化简 化简,4sin^2a(1-sin^2a)+cos^22a, 求证1+sin a+cos a+2sin acos a/1+sin a+cos a=sin a+cos a 化简:sin(-a)cos(2π+a)sin(-a-π) 化简sin^(a-30°)+sin^(a+30°)-sin^a化简sin^2(a-30°)+sin^2(a+30°)-sin^2a sin 2a+2sin方a/ 1+tan a =2sin a cos a 求证:sin 2a/1+sin a+cos a=sin a+cos a-1急 (cos a)^4+(sin a)^2*(sin a)^2+(sin a)^2=? (1-sin^6 a-cos^6 a)/(sin^2 a-sin^4 a)的化简结果, 急.三角函数：化简（sin^2a*cos^4a+sin^4acos^2a)/(1-sin^4a-cos^4a) sin^(丌/4-a)+sin^2(丌/4+a) 懂得进.证明,sina+sin(a+b)+sin(a+2b)+...sin(a+nb)=sin(a+ab/2)sin[(n+1)b/2]/sin(b/2) 化简：sin^4a+cos^2a-sin^2a-cos^4a 化简sin(-A-2派)