True or false: 1

True or false:
1. The constant field $\mathbf{i}+2\mathbf{k}$ is a gradient field.
2. For non-gradient fields, equipotentials meet streamlines at non-right angles.
3. In three dimensions the equipotentials are surfaces instead of curves.
4. $\mathbf{F}=x^2\mathbf{i}+y^2\mathbf{j}+z^2\mathbf{k}$ points outward from $(0,0,0)$ — a radial field.

Gilbert Strang, Calculus, 3rd edition (Wellesley-Cambridge Press; MIT OpenCourseWare RES.18-001) · §15.1 Vector Fields, #37