The height the ball bounces when dropped from a zero height
Step-by-step explanation:
The "initial value" of a function is usually the value of the function when the independent variable is zero. Here, that variable is the height from which the ball is dropped.
When the independent variable is zero, the "initial value" of the function would be the height the ball bounces when it is dropped from that (zero) height.
= 21 x 21 x 21 x 21 x 21 x 5 = 20 420 505