I suppose you mean

Differentiate one term at a time.
Rewrite the first term as

Then the product rule says

Then with the power and chain rules,

Simplify this a bit by factoring out
:

For the second term, recall that

Then by the chain rule,

So we have

and we can simplify this by factoring out
to end up with

The origin is 0,0 the y axis is the line going up, the x axis is the line going like this — the top right is quadrant 1 the one below it is quadrant 2 the one beside that is quadrant 3 and the one above that is quadrant 4
<span>This problem is solved using the chain rule.
the area of the square is f(t) and the length of the side is g(t)
f(t)=g(t)^2
g'(t)=5
Using the chain rule
f'(t)=2*g(t)*g'(t)
The value of g(t) is sqrt(49) which is 7.
g'(t) is given as 5 cm/s
f'(t)=2*7*5=14*5=70cm^2/s</span>