Evaluate the following definite integrals

Question

anonymous · Answer

$$\int\limits_{3}^{4}2\sin2x dx$$

anonymous · Answer

wolframalpha.com

myininaya · Answer

u=2x
du=2dx
if x=4, u=8
if x=3, u=6
$$\int\limits_{6}^{8}sinu du=-cosu|=-\cos8+\cos6$$

anonymous · Answer

yea thats what i got... my teacher must have put something in incorrectly...

myininaya · Answer

why?

anonymous · Answer

i dunno... ive done it like 10 times and i keep getting 1.11 (same as my tutor) but Lecturer got 0.88 :S:S:S

myininaya · Answer

did you have it in radians or degrees?

anonymous · Answer

radians and degrees gegrees i got .81 
or something like that but not .88

myininaya · Answer

i got 1.10 radians
and .004 in degrees
your teacher made a mistake

anonymous · Answer

yea... guessed as much lol.. >.< thanks though :D (currently writing cheat sheet for exam tomorrow) >.<