# Math Help - find the formula for the function described..

1. ## find the formula for the function described..

A function of the form y = a*sin(bt^2) whose first critical point for positive t occurs at t=1 and whose derivative is 3 when t = 2.

I tried to take the first derivative ( 2abtcos(bt^2)) ,but I didn't know how to apply the point I was given..... can someone help me with this problem? thanks in advance

2. Originally Posted by reaperx6
A function of the form y = a*sin(bt^2) whose first critical point for positive t occurs at t=1 and whose derivative is 3 when t = 2.

I tried to take the first derivative ( 2abtcos(bt^2)) ,but I didn't know how to apply the point I was given..... can someone help me with this problem? thanks in advance
You can use

$\frac{dy}{dt}= 2abt\cos(bt^2)$

$3= 2ab(2)\cos(b(2)^2)$