What is the y prime of:(adsbygoogle = window.adsbygoogle || []).push({});

A 15 foot board rests against a vertical wall. If the bottom of the board slides away from the wall at the rate of 3 feet per second, how fast is the area of the triangle formed by the board, the wall and the ground changing at the instant the bottom of the board is 9 feet from the wall?

I got this far:

y= square root of (225 - x^2)

I'm stuck after this step.

Can the answer for this be [(-9 yprime /2) + 18] square feet per second.

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# Homework Help: Finding y prime (derivative)

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