Найти полный дифференциал функции U=3x^2+5y^4-7z

[latex]U=3x^2+5y^4-7z \ dU=2*3xdx+5*4y^3dy-7dz=6xdx+20y^3dy-7dz \ [/latex]

[latex]u=3x^2+5y^4-7z\frac{partial u}{partial x}=3*2x+0-0=6x\frac{partial u}{partial y}=0+5*4y^3-0=20y^3\frac{partial u}{partial z}=0+0-7=-7\du=frac{partial u}{partial x}dx+frac{partial u}{partial y}dy+frac{partial u}{partial z}dz=6xdx+20y^3dy-7dz[/latex]