For the three-variable function f(x,y,z)=ysin(z)+x2f(x, y, z) = y \sin(z) + x^2f(x,y,z)=ysin(z)+x2, what is the partial derivative fzf_zfz?
ycos(z)y \cos(z)ycos(z)
cos(z)\cos(z)cos(z)
−ycos(z)-y \cos(z)−ycos(z)
ysin(z)y \sin(z)ysin(z)