.高数题已知函数z=(1/3)ln(x-y),x=sect,y=3 sint 求（dz/dt)

.高数题已知函数z=(1/3)ln(x-y),x=sect,y=3 sint 求（dz/dt) | t=π

人气：295 ℃　时间：2020-05-19 11:08:59

解答

z=(1/3)ln(sect-3sint)
dz/dt=(1/3)(secttant-3cost)/(sect-3sint)
t=π
dz/dt=(1/3)(3)/(1）=1