化简 sin(x-20°)+cos(x+70°)+sin(x+20°)sec(70°-x)麻烦稍微写下过程呐.

cos x/sin x+sin x/(1+cos x) 化简. cos(25°+x)cos(20°-x)-cos(65°-x)sin(20°-x) 化简(sin x+cos x-1)(sin x-cos x+1)/sin 2x 化简sin(x)(cos(x)+cos(3x)+cos(5x)+cos(7x)) 化简sin(x)cos(x)cos(2x) 化简sin(x)cos(x)cos(2x) sin x cos x cos 2x 化简 化简 cos^2(x)*sin^2(x)-sin^2(x) 化简sin^4x-sin^2x+cos^2x 化简:sin^4 x-sin^2 x+cos^2 x 化简 cos^(2)(x)*sin^(2)(x)-sin^(2)(x) 化简sin^4x+cos^2x 化简cos^4x+sin^4x 化简:cos^4(X)-sin^4(X) cos x/( 1-sin x)化简 化简(sin^2x-cos^4x+cos^2x-sin^4x)/(sin^2x-cos^6x+cos^2x-sin^6x) 化简cos(180°+x)*sin(x+360°)/[sin(-x-180°)*cos(-180°-x)] 化简sin(x-25°)sin(65°-x)+cos(x-25°)cos(65°-x)的结果为