求曲面x=2t,y=sint,z=cost平行于平面y+z=1的切线方程

求曲面x=2t,y=sint,z=cost平行于平面y+z=1的切线方程 高数!设z=e^(x-2y),而x=sint,y=t^3,求dz/dt 设z=e^(x-2y),而x=sint,y=t^3,求dz/dt 设z=x^2*y^3;,x=sint,y=e的t次方,求dz/dt Z=e(x-2y) X=sint Y等于T的平方 求dz/dt 求x=e^t*cost,y=e^t*sint所确定的函数的二阶导数,求讲解x't=(e^t)(sint+cost)y't=(e^t)(cost-sint)x''t=(e^t)(sint+cost+cost-sint)=2(e^t)costy''t=(e^t)(cost-sint-sint+cost)=-(e^t)sintdy/dx=(cost-sint)/(sint+cost)d^2 y/d(x^2)=d(dy/dx)/dx=(y''x 密度为1的螺线,x=cost,y=sint,z=2t(0 求z=2x+y的最大值,使式中的x y满足约束条件x^2/25+y^/16=1 不用参数法怎么做?x²/25 + y²/16 = 1可设x=5cost,y=4sint则z = 2x + y = 10cost + 4sint = √(100+16) * cos (t-a)→为什么?a是?其中cos a = 10/√(100+16) ,sin 设z=x^2-y^2,x=sint,y=cost,求dz/dt 微分z=e^x-2y,x=cost,y=sint,求：dz/dt 证明：f(x)=x*cos(x)不是周期函数证明：假设y=xcosx是周期函数,因为周期函数有f(x+T)=f(x)xcosx=（x+T)cos(x+T)=xcosx*cosT-xsinx*sinT+Tcosx*cosT-Tsinx*sinT所以cosT=1 T=kπ/2-xsinx*sinT+Tcosx*cosT-Tsinx*sinT=0-xsinx*sinT-Tsinx*si 设z=f(x,y)且x=t+sint,y=t^2,f(x,y)可微,则dz/dt设z=f(x,y)且x=t+sint,y=t^2,f(x,y)可微,求dz/dt sint t=x的三次方 求sint导数? 设z=xy+sint,而x=e^t,y=cost,求导数dz/dt求详细解答 x=(e^t)sint y=(e^t)cost 求d^2y/dx^2 matlab由三条曲线怎么绘制曲面图t由0到pi,第一条曲线,x=cos t,y=sin t,z=5 cos t第二条曲线x=cos t,y=cos t * sin t,z=8cos t第三条曲线x=cos t,y=sin t * cos t,z=5 sin t画出三维曲面图 如何用matlab画x=2sint,y=cost,z=4t,t=-pi:pi图象 求曲面Z=4-x^2-y^2平行于平面T:2x+2y+z=0的切面方程,并求此曲面到平面T的最长距离题没怎么读懂