已知2y-3與3x+1成正比例,則y與x的函數解析式可能是() A. y=3x+1B. y=32x+1C. y=32x+2D. y=3x+2

已知2y-3與3x+1成正比例,則y與x的函數解析式可能是() A. y=3x+1B. y=32x+1C. y=32x+2D. y=3x+2


∵2y-3與3x+1成正比例,則2y-3=k(3x+1),當k=1時,2y-3=3x+1,即y=32x+2.故選C.



z=arctan根號下x^y對x和y各求一階偏導


dz/dx=y*x^(y/2-1)/2(1+x^y)
dz/dy=lnx*x^(y/2)/2(1+x^y)



z=e^(uv)u=ln[根號(x^2+y^2)] v=arctan(y/x)
複合函數的偏導數或導數


u=ln[根號(x^2+y^2)]=1/2ln(x^2+y^2)z'x=ve^(uv)*1/[2(x^2+y^2)]*2x+ue^(uv)*1/(1+y^2/x^2)*(-y/x^2)=ve^(uv)*x/(x^2+y^2)-ue^(uv)*y/(x^2+y^2)(u,v自己代入)z'y=ve^(uv)*1/[2(x^2+y^2)]*2y+ue^(uv)*1/(1+y^2/x…