Question

The integral of cos(u^2)du from 5x to cos(x). Not looking for an answer, looking for steps.

Answer 1

can we sub z^(1/2) for x ?

Answer 2

Dunno.

Answer 3

err.... i meant sub it for u lol

Answer 4

Then what do we get cos(x^4)?

Answer 5

if u = z^(1/2)
then du = \(\frac{1}{2z^{1/2}}\) dz
\[\int\frac{cos(z)}{2z^{1/2}}dz\]

Answer 6

why does the latex z look like an x ?

Answer 7

That looks like it just made the problem worse.

Answer 8

Nevermind, Z for X

Answer 9

Do I have to put the limits in terms of x even though they have x's in them?

Answer 10

lol .... sometimes it gets better sometimes not

Answer 11

the limits arent the issue are they? if we can integrate the cos(u^2) the limits are a sinch

Answer 12

Well when you use U sub with limits you usually change them right?

Answer 13

table of ints says:

cos(ax^2) goes to: sqrt(pi/2a) C(sqrt{a}); but i got no idea what the C means

Answer 14

i always mess it up when I change limits, so I just convert back to the original in the end

Answer 15

So I don't need to change the limits, I only needed to put the integral itself into terms of x?

Answer 16

the variable of the integral just tells you what to do to the limits after integrating; spose it ints up to sin(u); then whenever you see a u, replace it with the limit to get:

sin(cos(x)) - sin(5x)

Answer 17

wolfram gives me the same fresnel integral

Answer 18

Answer is Sin(x)*cos(cos^2x)+5(cos(25x^2)) @_@

Answer 19

is that from an answer sheet?

Answer 20

Yea

Answer 21

i cant see how its done ... :)