Question 18
Let $z = z(u, v, t)$ and $u = u(x, y)$, $v = v(x, y)$, $x = x(t, s)$, and $y = y(s)$. The expression for $\frac{\partial z}{\partial t}$, as given by the chain rule, has how many terms?
Three terms
Four terms
Five terms
Six terms
Seven terms
Nine terms
None of the above