A community for students.
Here's the question you clicked on:
 0 viewing
dfresenius
 2 years ago
Integral with trig functions
dfresenius
 2 years ago
Integral with trig functions

This Question is Closed

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1361089150658:dw

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1361089181888:dw

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1or would it be cos^xcos5x

dumbcow
 2 years ago
Best ResponseYou've already chosen the best response.0no cant combine them...it would just be \[\cos(5x)  \cos^{2} x \cos(5x)\]

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1so left integral is easy

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1hmm no i cant do that

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1that 5x is just blowing my mind

dumbcow
 2 years ago
Best ResponseYou've already chosen the best response.0yeah im not sure of way to do it without expanding out the cos(5x) ..... which would be messy

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.2huh ? integral of cos 5x is just sin 5x/5 +c .

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1361089595564:dw

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1yA i know that integral, but its the cos^2 that is messin me up

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.2ok, you need to used \(\sin^2x = (1 \cos2x )/2\)

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.2then, for cos 2x cos 7x there is a standard formula for , cos A cos B =...

dumbcow
 2 years ago
Best ResponseYou've already chosen the best response.0ahh i always forget sum to product rules ... anyway, here is solution http://www.wolframalpha.com/input/?i=integrate+sin^2%28x%29+cos%285x%29+dx

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1361090139384:dw

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1ok so here is another, im thinking with this one i can multiply by a 1/2 and use the identity sin2x

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.2sin x cos x = (sin 2x) /2 then we have formula for sin A cos B

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1361090244648:dw

sami21
 2 years ago
Best ResponseYou've already chosen the best response.0for the first question by parts can also be used . \[\Large \frac{1}{5}\sin^2(x)\sin(5x)\frac{2}{5}\int\limits \sin(x)\sin(5x)\cos(x)dx\]

.Sam.
 2 years ago
Best ResponseYou've already chosen the best response.0\[( \sin A ) ( \sin B )=\frac{1}{2} (\cos (A B )\cos (A +B ))\]

.Sam.
 2 years ago
Best ResponseYou've already chosen the best response.0But there's still a lot of work if you do this

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1361090429038:dw

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1361090501054:dw

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.2why  *minus* in between ?

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1integral of sin is cosx

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.2both of  from that you have factored out, right ? to make 1/4 ?

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1well, before i took integral

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1361090806081:dw

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1those will both be negative right?

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.2integral of those will be negative, yes, right.

dfresenius
 2 years ago
Best ResponseYou've already chosen the best response.1ok thats all i got, thank you so much both of you for helping me out, big test this friday
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.