Answer
a.
The graph of g is obtained by shifting the graph of f(x,y) up (along the z-axis) by two units.
b.
Stretch f(x,y) vertically (along the z-axis) by a factor of 2.
c.
Reflect f(x,y) about the xy-plane.
d.
Reflect f(x,y) about the xy-plane and shift upward by 2 units.
Work Step by Step
In analogy with 2D graphs of single-variable functions:
$f(x)\pm c$ meant raising/lowering the graph ( in the y-direction).
For f(x,y), "up" and "down" means along the z-axis.
$c\cdot f(x)$ was either stretching or compressing in the y direction.
Here, the stretching and compressing is in the z-direction.
$-f(x)$ was reflected about the x-axis.
Here, we reflect about the xy-plane.
