Question

Please see link:
http://s1084.photobucket.com/albums/j409/QRAWarrior/?action=view¤t=MATA30Y-Attempt.png

Answer 1

http://i1084.photobucket.com/albums/j409/QRAWarrior/MATA30Y-Attempt.png

Answer 2

^ direct link above

Answer 3

I showed the right hand side, but I don't know how I would show left. The minimum value that sin^2(x) can be is 0, but that just messes things up.

Answer 4

The only problem here is that you plugged in a value for x in the integral before you evaluated it
leave x in the integral and you can show that\[\int xdx\]is in the range you are looking for. Since sin^2 can only make the value smaller, the integral will always be in that range

Answer 5

also sin^2 cannot be zero because the interval is from pi/4 to pi/2, and sin>0 in that range