# Antiderivative help

1. Feb 10, 2008

### unhip_crayon

1. The problem statement, all variables and given/known data
What is the anti derivative of

-5.4sin(3t)

3. The attempt at a solution

I have not done this in a while and i cant seem to find my prev. notes but is it not

-5.4cos(3t)*3 + C

2. Feb 10, 2008

### rock.freak667

Divide by the differential in the brackets...

and $\frac{d}{dx}(cosX)=-sinX$

3. Feb 10, 2008

### PowerIso

Well, here are some little hints.

Take -5.4 out of the integral.

Let u = 3t du = 3dt.

So then you have (-5.4/3) Integral of sin(u)du.

Integrate and place the u with 3t once you are finished. (Note the integral of sin is NOT just cosin.)

4. Feb 10, 2008

### unhip_crayon

ahhh right...so the correct answer should be

1.8cos3t

thanks