# Thread: MIT integration bee questions

1. ## MIT integration bee questions

#1

[3x^3 -9]^(1/2)
______________
x

#2

[8x+6x^(5/2)]^(1/2)

I think we need to use substitution to solve these....anybody?

2. Originally Posted by mag6
#1

[3x^3 -9]^(1/2)
______________
x

#2

[8x+6x^(5/2)]^(1/2)

I think we need to use substitution to solve these....anybody?

The first one , substitute $\displaystyle x^3 = t$

The second one , first let $\displaystyle x = t^2$ then let $\displaystyle t^3 = u$ or you just let $\displaystyle x = u^{\frac{2}{3} }$

3. Originally Posted by simplependulum
The first one , substitute $\displaystyle x^3 = t$

The second one , first let $\displaystyle x = t^2$ then let $\displaystyle t^3 = u$ or you just let $\displaystyle x = u^{\frac{2}{3} }$
nope.....that's not working....none of them.

i tried taking u= x^3 - 3 in the first one but that's not working either.

4. For the first one, do $\displaystyle s=\sqrt{3x^3-9}$. For the second, $\displaystyle s=6x^{3/2}+8$.

For the first one, do $\displaystyle s=\sqrt{3x^3-9}$. For the second, $\displaystyle s=6x^{3/2}+8$.