1.3/2cos x-√￣3/2sin x;2.sin347°cos148°+sin77°cos58°

化简（1)√3sin x+cos x (2）√2(sin x-cos x) （3）√2cos x-√6sin x 已知sin(x)+3cos(x)=2,求sin(x)-cos(x)/sin(x)+cos(x)=? sin[cos^2(x^3+x)],求导 √3cos^2x-sin^2x化简 化简√3sin (x/2)+cos(x/2) 第一题1/2cos x-√3/2sin x 第二题√3sin x+cos x 第三题√2[sin x-cos x] 第四题√2cos x-√6sin x 2sin^2x - 5sin x cos x=3 cos^2x,求X, 化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x 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]的值第一题1/2cos x-√3/2sin x第二题√3sin x+cos x第三题√2[sin x-cos x]第四题√2cos x-√6sin x 化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x) 化简 1/2cos x-根号3/2sin x 根3sin x+cos x 证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4 当cos^2x-cos^2y=√3/2时,求sin(x+y）×sin(x-y) sin^3 x -cos^3 x sin^3 x -cos^3 x =(sin x -cos x )(sin^2 x +sin x*cos x +cos^2 x )问下这个是个公式还是什么?怎么样算出来的? 2(sin^6x+cos^6)-3(sin^4x+cos^4x) 1.3/2cos x-√￣3/2sin x;2.sin347°cos148°+sin77°cos58° (sin x*sin 3x)sin^2 x+（cos x*cos 3x)cos^2 x 如何变到1/2[(cos 2x-cos4x)sin^2x+(cos2x+cos4x)cos^2x] Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y)