sin（x+a)*sin(x-a)应如何计算

sin（x+a)*sin(x-a)应如何计算 求当x趋近于a时,(sin x - sin a) /sin (x - a)的极限 sin(x+a)-sinx=2sin(a/2)cos(x+a/2),这个如何得到的, limx->a (sinx-sina)/sin(x-a) lim x趋于0 [sin(a+x)sin(a+2x)-sin^2a]/x 求极限不用洛必达法则 lim→x-a (sin^2x-sin^2a)/(x-a) 求极限 ( sin(x)-sin(a) )/(x-a) 当x 趋于a时 求当x趋近于a时,(sin x - sin a) / (x - a)的极限 sinx+sina如何化成2sin(x-a)/2cos(a+x)/2 sinA=x,sin(A/2)=? y=sin(2x+a)(0 y=sin(2x+a)（0 如果f(cos x)=sin 3x,那么f(sin x)等于A.sin 3x B.-sin 3x Ccos 3x D-cos 3x C语言求三角函数f(x,y,z)=sin(x)/(sin(x-y)*sin(x-z))+sin(y)/(sin(y-x)*sin(y-z))+sin(z)/(sin(z-x)*sin(z-y))代码#include #include double fun(double x,double y,double z){double a,b,c,sum;a=sin(x)/(sin(x-y)*sin(x-z));b=sin(y)/(sin(y-x)*sin(y-z));c 3道求极限的题目1.sin 2x/sin 5x （x→0）2.(sin x - sin a)/(x - a) (x→a)3.sin ωx/x (x→0) 【a+x*sin(1/x)】的极限,x>0 一道不定积分题求解：sin(x+a)/sin(x+b)关于x的不定积分 已知函数f x=a(2sin ²x/2+sin x)+b