Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing

This Question is Closed

RD⁴² Group TitleBest ResponseYou've already chosen the best response.2
Are you sure it's not (cosx)(tanx+sinx cosx) = sinx + sinx cos²x ?
 one year ago

rahrah Group TitleBest ResponseYou've already chosen the best response.0
oh crap, its actually (cosx)(tanx+sinx cotx)=sinx+cos^2x
 one year ago

RD⁴² Group TitleBest ResponseYou've already chosen the best response.2
We know that \(\tan x = \dfrac{\sin x}{\cos x}\) and \(\cot x = \dfrac{\cos x}{\sin x}\) So \((\cos x)(\tan x+\sin x \cot x) = (\cos x)\left(\dfrac{\sin x}{\cos x} + \sin x\cdot\dfrac{\cos x}{\sin x}\right)\) \(=(\cos x)\left(\dfrac{\sin x}{\cos x} + \cos x\right)\) \( = \boxed{\sin x + \cos^2 x}\)
 one year ago

RD⁴² Group TitleBest ResponseYou've already chosen the best response.2
\[\Huge\text{Q.E.D.}\]
 one year ago

rahrah Group TitleBest ResponseYou've already chosen the best response.0
Q.E.D. ? Thanks a lot for the help otherwise
 one year ago

RD⁴² Group TitleBest ResponseYou've already chosen the best response.2
http://en.wikipedia.org/wiki/Q.E.D.
 one year ago

rahrah Group TitleBest ResponseYou've already chosen the best response.0
wait, how'd you get sinx + cos^2 at the end? shouldn't sinx/cosx cross out the + cosx?
 one year ago

RD⁴² Group TitleBest ResponseYou've already chosen the best response.2
No, because it's just addition. you can't cancel cos x out like that.dw:1362452530886:dw
 one year ago

rahrah Group TitleBest ResponseYou've already chosen the best response.0
shouldnt that make the end result be tanx cosx + (cosx)^2? how did we get sin from the tan?
 one year ago

RD⁴² Group TitleBest ResponseYou've already chosen the best response.2
\(\tan x = \dfrac{\sin x}{\cos x}\) right? So \(\tan x\cos x\ = \dfrac{\sin x}{\cos x}\cdot \cos x = \sin x\) And cos²x is just another way to write (cos x)²
 one year ago

rahrah Group TitleBest ResponseYou've already chosen the best response.0
oh, i get it now. Thanks a lot for all your help!
 one year ago

RD⁴² Group TitleBest ResponseYou've already chosen the best response.2
Glad I helped.
 one year ago
See more questions >>>
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.