sin x 3 cos x =2怎么解?

sin x 3 cos x =2怎么解? 怎么证明2(1-sin x)(1+cos x)=(1-sin x+cos x)^2 cos(sin x)怎么解 已知sin(x)+3cos(x)=2,求sin(x)-cos(x)/sin(x)+cos(x)=? cos(3x/2)cos(x/2)-sin(3x/2)sin(x/2)=cos(3x/2+x/2)=cos2x 怎么得出这个结果的? 2sin^2x - 5sin x cos x=3 cos^2x,求X, 解sin 2x=cos 3x方程 y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)的最值 用向量解 化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x) 证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4 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? 怎么解sin(x)*cos(x)=0.5 怎么解方程cos(x)+sin(x)=0 (sin^2x+cos^2x )(sin^2x-cos^2x)怎么得sin^2x-cos^2x? 急,matlab解非线性方程组用什么函数呢 方程如下所示：(cos(x(1))*cos(x(3))-sin(x(1))*cos(x(2))*sin(x(3)))*(194-x(4))*x(7)+(cos(x(1))*sin(x(3))+sin(x(1))*cos(x(2))*cos(x(3)))*(145-x(5))*x(7)+sin(x(1))*sin(x(2))*x(6)*x(7)-1=0;(-sin(x(1 已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x 证明tan^2x-sin^2x=tan^2x*sin^2x解sin^2x sin^2x--------- - -----------cos^2x 1等于sin^2x sin^2x--------- - -----------cos^2c cos^2x+sin^2x接下来还能做吗?这道题还有其他证法吗?怎么能等式两边同除呢？这是证明题，证 sin(5x)-sin(3x)= 根号2cos(4x)1.sin(5x)-sin(3x)= （根号2）cos(4x)解方程2.sin（x）+sin(2x)+sin(3x)=1+cos(x)+cos(2x)