一个是平面的~几个是放在坐标系中的~~ 还有sin(x,y,z)那就成空间的啦
求导计算过程如下:y=sin(x+y) 两边求导:y'=cos(x+y)*(1+y') y'=cos(x+y)+y'cos(x+y) y'[1-cos(x+y)]=cos(x+y) y'=cos(x+y)/[1-cos(x+y)].
sinxcosy+cosxsiny
y=sin|x|当x>=0时,就是y=sin|x|=sinx,所以x轴右侧图像就是y=sinx.当x=0时,保持y=sinx图像不变,sinx
∫(sin x)^5(cos x)^3dx=∫(sinx)^5(1-sinx)dsinx=∫(-sin^7x+sin^5x)dsinx=-(sinx)^8/8+(sinx)^6/6+c
sin(x-y)=sinx cosy - cosx siny
sin的定义就是y值(在单位圆中) 因为它是角的对边除以斜边,斜边长为1
sin(x-y)是否一定等于-sin(y-x)??sin(xy)是否一定等于-sin(-xy)??为什么?解:sin(x-y)=sin[-(y-x)]=-sin(y-x)对任何x,y都成立;sin(xy)=sin[-(-(xy)]=-sin(-xy)对任何x,y都成立.这是三角函数诱导公式之一:sin(-α)=-sinα,α∈R
复合函数求导法则,看成sinu,u=x+y求导,=cosu*u'=cos(x+y)*(1+y')
解:sin(x+y)sin(x-y) =-1/2(cos(x+y+x-y)cos(x+y-x+y)) =-1/2(cos2xcos2y) =-1/2(1-2(sinx)^2-1+2(siny)^2) =(sinx)^2-(siny)^2