A community for students. Sign up today!
Here's the question you clicked on:
 0 viewing

This Question is Closed

SuckMyEsophagus
 2 years ago
Best ResponseYou've already chosen the best response.0Let u = cos x du = sin x dx then, "integral [u^3 du]" or " integral [u^3 du] " = (u^4)/4 + C = (cos^4 x)/4 + C

kaiz122
 2 years ago
Best ResponseYou've already chosen the best response.0i have a question, sin x is in the denominator, how does it become the du then?

SuckMyEsophagus
 2 years ago
Best ResponseYou've already chosen the best response.0Because everything is substituted and then flipped :)

kaiz122
 2 years ago
Best ResponseYou've already chosen the best response.0i tried checking it by differentiation, then i got (cos^3x )(sinx)

SuckMyEsophagus
 2 years ago
Best ResponseYou've already chosen the best response.0Are you using your calculator?

SuckMyEsophagus
 2 years ago
Best ResponseYou've already chosen the best response.0You can integrate this directly, just notice that differentiating cos^4(x) gives you 4cos^3(x)sin(x) by the chain rule. Hence the integral of cos^3(x)sin(x) is 1/4 cos^4(x)

kaiz122
 2 years ago
Best ResponseYou've already chosen the best response.0i still don't get it, how does sin x in the denominator becomes du? dx/sinx is not equal to sinx dx right.

SuckMyEsophagus
 2 years ago
Best ResponseYou've already chosen the best response.0No their not the equal

kaiz122
 2 years ago
Best ResponseYou've already chosen the best response.0@saifoo.khan can you please help me here

AravindG
 2 years ago
Best ResponseYou've already chosen the best response.0use @AravindG if u have any integration qns in future
Ask your own question
Ask a QuestionFind 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.