A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 3 years ago
cos theta = 4/5, 0˚< theta < 90˚ use the information given to find sin2theta, cos2theta, and tan 2theta
anonymous
 3 years ago
cos theta = 4/5, 0˚< theta < 90˚ use the information given to find sin2theta, cos2theta, and tan 2theta

This Question is Closed

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0you need \(\sin(\theta)\) so compute these do you know how to find it?

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0dw:1358823887705:dw

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0sin 2 theta = 2 sin theta cos theta cos 2 theta = 2 cos ^2 theta  1 tan 2 theta = sin 2 theta / cos 2 theta

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0do i plug in 4/5 where theta is?

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0If costheta=4/5 then sintheta= 3/5 \[\sin2\theta=2\sin\theta \cos\theta\]

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0there is a picture of an angle whose cosine is \(\frac{4}{5}\) you find the third side by pythagoras, or recalling the 3  4  5 right triangle this tells you \(\sin(\theta)=\frac{3}{5}\)

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0so 2 sin theta = 2 sin 3/5 cos 4/5

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0no do not make that mistake, it is a common one do not use \(\theta=\frac{4}{5}\) use \(\cos(\theta)=\frac{4}{5}\) so \[\sin(2\theta)=2\times \frac{4}{5}\times \frac{3}{5}\]

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0no not the cosine and sine of those numbers, those numbers ARE the cosine and sine

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0use the numbers themselves, they are your sines and cosines

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0im still confused a little ..
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.