Δy=sin(x+Δx)-sinx=2cos(x+Δx/2)sin Δx/2
Δy=sin(x+Δx)-sinx=2cos(x+Δx/2)sin Δx/2
sinx 导数 sin(x+Δx)-sinx=2cos(x+Δx/2)*sin(Δx/2)是怎么得来的?
sin(x+△x)-sinx=2sin△x/2.cos(x+△x/2)
证明 [sin(2x+y)/sinx]-2cos(x+y)=siny/sinx
求证:sin(2x+y)/sinx-2cos(x+y)=siny/sinx
请问怎么证明sinX+sin(X+Y)+sin(X+2Y)/cosX+cos(X+Y)+cos(X+2Y)=tan(X+
证明sinx+siny+sinz-sin(x+y+z)=4sin((x+y)/2)sin((x+y)/2)sin((x+
化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
sin(x+y)sin(x-y)=k,求cos^2x-cos^2y
f(x)=2cos*sin(x+π/3)-^3sin^2x+sinx*cosx
证明成立:[cos(3x)-sin(3x)]/(cosx+sinx)=1-2sin(2x).