# Integral Question- Am I doing it correctly?

• Feb 11th 2010, 05:31 PM
skboss
Integral Question- Am I doing it correctly?
I am not sure how to Integrate this type of problems--

integral squareroot(t^2+t) dt

and integral (5t^2-6)dt

Attempts:

integral sqareroot(t^2+t) dt= 2/3 ((t^2+t) ^(3/2) (2t+1)

And solve the other one same way.

Is that right?

(Headbang) (I am not sure if I differentiate the middle portion when integrating)(Headbang)
• Feb 11th 2010, 05:49 PM
skeeter
Quote:

Originally Posted by skboss
I am not sure how to Integrate this type of problems--

integral squareroot(t^2+t) dt ... ???

and integral (5t^2-6)dt

Attempts:

integral sqareroot(t^2+1) dt= 2/3 ((t^2+1) ^(3/2) 2t no

And solve the other one same way.

Is that right?

(Headbang) (I am not sure if I differentiate the middle portion when integrating)(Headbang)

$\displaystyle \int \sqrt{t^2+1} \, dt$ requires a trig substitution.

$\displaystyle \int 5t^2 - 6 \, dt = \frac{5t^3}{3} - 6t + C$
• Feb 11th 2010, 05:58 PM
skboss
Sorry I posted the question wrong. It should be

integral squareroot(t^2+t) dt
• Feb 11th 2010, 06:04 PM
skeeter
Quote:

Originally Posted by skboss
Sorry I posted the question wrong. It should be

integral squareroot(t^2+t) dt

you just made it more difficult ...

use ... Wolfram Mathematica Online Integrator to see the antiderivative.
• Feb 11th 2010, 07:32 PM
skboss
Haha, sorry. Thanks for the link though.