Question

Please help :)

Answer 1

http://screencast.com/t/v188H7y1g

the box part

Answer 2

or rather how do i integrate

\[\int\limits_{0}^{\pi/2} \cos(4\theta)+4\cos(2\theta)\]

Answer 3

@satellite73 @robtobey

Answer 4

god do i hate these

Answer 5

oh actually this is not bad
a mental u - sub for both

Answer 6

?

Answer 7

\[\int\cos(4\theta)+4\cos(2\theta)\]
\[=\int\cos(4\theta)d\theta+4\int\cos(2\theta)d\theta\] is a start

Answer 8

okay

Answer 9

then the anti derivative of \(\cos(4\theta)\) is \(\frac{1}{4}\sin(4\theta)\)

Answer 10

yeah

Answer 11

similarly the anti derivative of \(\cos(2\theta)\) is \(\frac{1}{2}\sin(2\theta)\)

Answer 12

plug and play

Answer 13

so whts the final answer

Answer 14

i have no idea
you have to plug in the upper limit, plug in the lower limit, and subtract

Answer 15

\[\frac{1}{4}(\sin(4\theta))+2(\sin(2\theta))\]

Answer 16

this is the final integration

Answer 17

can u please check coz im not getting the answer

Answer 18

sorry, you are right

Answer 19

can u put the limits, and let me know the final answer please

Answer 20

\[\frac{1}{4}(\sin(4\theta))+2(\sin(2\theta))\] looks right
now at 0 you get a big fat 0

Answer 21

at \(\frac{\pi}{2}\) you get
\[\frac{1}{4}\sin(2\pi)+2\sin(\pi)=0\] as well

Answer 22

cn u chck this as well the marking scheme http://screencast.com/t/8M7mvbM935E

Answer 23

thts why im confused

Answer 24

for a final answer of zero
all that work for nothing

Answer 25

hmm so wts wrng with the making scheme

Answer 26

i don't understand at all what the question is from the link you sent

Answer 27

lol i found it out, thanks anyway:)

Answer 28

yw