(xy'-y)cos^2(y/x)+x=0 求齐次方程的通解

x(y^2+2xyy')=cos(xy^2) 细节 cos(xy^2)=x+2y求导 y=x^1/x求导 求解微分方程xy'ln(x)sin(y)+cos(y)(1-x*cos(y))=0 (xy'-y)cos^2(y/x)+x=0 求齐次方程的通解 设u={cos(x^2)}/y +(xy)^(y/x) 求du ) y=cos(x-y)求一阶导数y=cos(x-y)求三阶导数y=e^-xy=(e^2x)(sinx) |x|/x+y/|y|+xy/|xy|= 若方程cos(xy)-x^2·y=1 确定y是x的函数,求y''|(1,0) cos(xy)-ln[(x+y)/y]=y当x=0时怎么求导, y=x+e^y和y=cos(xy)-x的微分,详解3Q 证明COS（X+Y）COS（X-Y）=COS^2X-SIN^2Y 证明cos(x+y)cos(x-y)= cos^2(x)-sin^2(y) cos(xy)+x^6=y^6 求导 y=cos（xy）-x 求微分 xy^3-cos(x+y)=1,求dy xy^3-cos(x+y)=1,求dy 1+cos^2(2x+3y-1)=(x^2+y^2+2(x+1)(1-y))/(x-y+1) 求实数xy最小值写明方法 证明当(x,y)趋向于(0,0)时,f(x,y)=(1-cos(x^2+y))/(x+y)xy 的极限不存在, 谢谢~