Consider a continuous function f such that F'(x) = f(x) for all real values of x. Find the integral evaluated from 2 to 7 of f(5x)dx. Any calc people get this?

Question

anonymous · Answer

clearly you are not expected to find a number, right?

anonymous · Answer

change the variable $u=5x$

anonymous · Answer

and $du=5dx$ so $\frac{1}{5}du=dx$ also change the limits of integration $u(2)=5\times 2=10$ and $u(7)=35$ then rewrite the integral as 
$$\frac{1}{5}\int_{10}^{35}f(u)du$$

anonymous · Answer

Umm so my answers are
A) 5F(7) - 5F(2)
B) (1/5)F(7) - (1/5)F(2)
C) 5F(35)- F(10)
E) (1/5)F(35) - (1/5)F(10)

anonymous · Answer

D) F(35) - F(10)