Scientific notation is written in the form a*10^n. What must be true about the a value? It can't be longer than 2 digits
It has to be greater than 100
It must be positive
It has to be a single digit between 1 and 10

It has to be a single digit between 1 and 10

Step-by-step explanation:

Given

From the complete question, we have:

--- radius

Required

Expression for the height of the roller coaster

We have:

--- equation of circle

Substitute 30 for r

Since the roller coaster is half of the circle, the height is defined by y.

So: make y the subject

Take square roots

Hence, the height is: