# Math Help - A problem featuring area of a square and rate of change.

1. ## A problem featuring area of a square and rate of change.

the length of a rectangle is given by 6t+ 5 and its height is $sqrt(t)$, where t is time in seconds and the dimensions are in centimeters. Find the rate of change with respect to time.

I am not really quite sure how to do rate of change.. I have read over the examples given for rate of change in the book however, it seems vague and borderline unrelated.. Their problem was dealing with speed and velocity..

2. Are you finding the rate of change of the area?

$A = (6t+5)\sqrt{t}$.

The rate of change of the area is the derivative of this function.

3. I gave you everything the book gave me to be honest.

So from here I am guessing I would just use the product rule to find the derivative from what you gave me?

4. The derivative IS the rate of change $dy/dx$ is the rate of change of y with respect to the change in x... in this case your independent variable is time. so just find $dA/dt$

Yes use the product rule.