Answer:
The vertex is b
Step-by-step explanation:
If you're going to use technology (Brainly) to solve this problem, you might find you get a quicker answer using the technology of your graphing calculator.
It is often convenient to cast the problem in the form f(θ) = 0. You can do that by adding 1 to both sides of the equation.

No she is not correct she needs to go back to school and learn math