# Thread: Upper and Lower bounds... Conceptual

1. ## Upper and Lower bounds... Conceptual

Suppose we know that $\displaystyle 1 \le \int_{0}^{4} g(x)dx \le 10$. Determine the best possible upper and lower bounds for $\displaystyle \int_{0}^{2} xg(x^2)dx$ that can be deduced from this information. Justify your answer.

Again, I've no idea where to really start on this one... if someone could help me through it I'd appreciate it.

2. Originally Posted by ebonyscythe
Suppose we know that $\displaystyle 1 \le \int_{0}^{4} g(x)dx \le 10$. Determine the best possible upper and lower bounds for $\displaystyle \int_{0}^{2} xg(x^2)dx$ that can be deduced from this information. Justify your answer.

Again, I've no idea where to really start on this one... if someone could help me through it I'd appreciate it.
this is a substitution problem cleverly disguised. try the substitution u = x^2 (remember to change the limits also) and see what you get

3. Is it between .5 and 5?

4. Originally Posted by angel.white
Is it between .5 and 5?
yes. inclusive, of course

good job

5. Originally Posted by Jhevon
yes. inclusive, of course

good job
Appreciate it, yesterday I didn't even know about changing the interval O.o

It's amazing how I learn so much more from reading through questions on this site, than from studying my book.