sin(x+▲x)-sinx怎么变成2cos(x+▲x/2)sin(▲x/2)
sin(x+△x)-sinx=2sin△x/2.cos(x+△x/2)
(sin^2x+cos^2x )(sin^2x-cos^2x)怎么得sin^2x-cos^2x?
若|sinx|>|cosx|,则sin^2 x>cos^2 x
求化简(sinx+tanx)/cos^2x+sin^2x+cosx
sinx*( cos x)^3/(1+sin^2x)的不定积分
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
f(x)=2cos*sin(x+π/3)-^3sin^2x+sinx*cosx
证明成立:[cos(3x)-sin(3x)]/(cosx+sinx)=1-2sin(2x).
求证:Sin^2 x / (sinx-cosx) - (sin x + cos x)/(ta
lim(sin(x^2*cos(1/x)))/x怎么做?
sinx 导数 sin(x+Δx)-sinx=2cos(x+Δx/2)*sin(Δx/2)是怎么得来的?
化简 cos^2(x)*sin^2(x)-sin^2(x)