# Thread: Integral Property Help!

1. ## Integral Property Help!

I have no idea what the property this problem is refering to. But i did find out that if i plug 3 and the 2 in f(2x+1) i get F(7) - (F5)

2. ## Re: Integral Property Help!

$u=2x+1$

$du=2 \, dx$

$\displaystyle \dfrac{1}{2} \int_2^3 f(2x+1) \cdot 2 \, dx = 10$

substitute and reset the limits of integration ...

$\displaystyle \dfrac{1}{2} \int_5^7 f(u) \, du = 10$

Note that $\displaystyle \int_5^7 f(u) \, du = \int_5^7 f(x) \, dx$

3. ## Re: Integral Property Help!

Wow, you guys are godly. Like, how do you figure it out just from seeing the question! xD thanks so much

4. ## Re: Integral Property Help!

The fact that you are told the integral of f(2x+ 1) while normally you do integrals of f(x) should have been a give away!