Thread: [SOLVED] Rectangle intersecting parabola, what are dimensions of rectangle with large

Question:
A rectangle is inscribed with its base on the x-axis and its upper corners on the parabola . What are the dimensions of such a rectangle with the greatest possible area?

Answer:
Width = 4
Height =8

I feel like I'm close to solving the problem but not quite there. I attached my work so far but I do not know what to do from here.

Any help would be greatly appreciated!
Thanks in advance!

Edit: I was doing same problem with different numbers so the numbers will be different on my work actually (I just realized) but I'd appreciate if someone could help me grasp the concept and I can do the calculations myself.

Actually, I solved it.