Which of the following functions satisfy the partial differential equation:

$\frac{\partial u}{\partial x} = ut$.

 1. $u(x,t) = e^{xt}$
 2. $u(x,t) = \sin(x+t)$
 3. $u(x,t) = xt$
 4. $u(x,t) = e^{x+t}$
 5. $u(x,t) = \sin(xt)$
 6. $u(x,t) = x+t$

Enter T or F depending on whether the statement is true or false. (You must enter T or F -- True and False will not work.)