# Math Help - Derivatives With Square Roots

1. ## Derivatives With Square Roots

the problem is:
if v(t)=sqr root(t^7)-sqr root(t) find the second derivative v"t.

i differentiated it and came up with 7/2t^5/2 - 1/2t^-1/2. but what does it mean to find the second derivative? and am i even doing it right?

2. You did that correctly. To find your 2nd derivative just take the derivative of your first derivative.

3. ooo how do i do that?

4. $\frac{7t^{\frac{5}{2}}}{2} - \frac{1}{2\sqrt{t}}$

Now take the derivative again using the power rule.

$\bigg(\frac{35}{4}\bigg)t^{\frac{3}{2}}~+~\frac{1} {4}t^{\frac{-3}{2}}$