高数lim【(sinx—siny)除以sin(x-y)】,x趋向于y,y不等于0
证明sin(x+y)sin(x-y)=sinx-siny
求函数z=sinx+siny+sin(x+y)(0
求sin(x+y)=sinx+siny的导数
lim((x^2)y)/(x^4+y^2),x和y都趋向于0
求下列导数:sin(x+y)=sinx+siny e^x+x=e^y+y
证明sinx+siny+sinz-sin(x+y+z)=4sin((x+y)/2)sin((x+y)/2)sin((x+
三角不等式证明证明sin(x+y)+sin(y+z)+sin(z+x)>sinx+siny+sinz+sin(x+y+z
证明 [sin(2x+y)/sinx]-2cos(x+y)=siny/sinx
求证:sin(2x+y)/sinx-2cos(x+y)=siny/sinx
高数 求当x趋向于0 y趋向于0时(x*x+y*y)/e的(x+y)次方的极限?
证明sin(x+y)sin(x-y)=(sinx)^2-(siny)^2.
证明:对x不等于y,恒有|sinx-siny|< |x-y|