A community for students.
Here's the question you clicked on:
 0 viewing
Life
 2 years ago
if x is a positive acute angle and cos x = radical 3/4, what is the exact value of sin x?
Life
 2 years ago
if x is a positive acute angle and cos x = radical 3/4, what is the exact value of sin x?

This Question is Closed

maym0Re97
 2 years ago
Best ResponseYou've already chosen the best response.2Mk so cos is adjacent over hypotenuse, dw:1352794400088:dw, now you just have to use Pythagorean theorem to solve for the last side. Sin is opposite over hypotenuse, so you're going to take the value you found from Pythagorean theorem and put that over 4 (the hypotenuse value)

maym0Re97
 2 years ago
Best ResponseYou've already chosen the best response.2dw:1352794508956:dw

Life
 2 years ago
Best ResponseYou've already chosen the best response.0i got 5/4 but thats not one of the choices. do you see where i went wrong?

Life
 2 years ago
Best ResponseYou've already chosen the best response.0one of the choices are 4/5 but im not sure, because i found the leg using the pythagorean theorem and got b(squared) = 25 which makes b= 5 and then over the hypotenuse which gave me 5/4

maym0Re97
 2 years ago
Best ResponseYou've already chosen the best response.2Hrm. Ok. Uhhh what are all the choices?

Life
 2 years ago
Best ResponseYou've already chosen the best response.0sqrt 3/5, sqrt 13/4, 3/5, 4/5

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.0alternative way: sin^2 x + cos^2 x = 1

maym0Re97
 2 years ago
Best ResponseYou've already chosen the best response.2You shouldn't be getting 5 for the last leg, because Pyth, should give you \[4^{2}=\sqrt{13}^{2}+x ^{2}\], which then becomes \[16=3+x ^{2}\], then \[13=x\], so x = sqrt 13.

maym0Re97
 2 years ago
Best ResponseYou've already chosen the best response.2Woops for the first equation it should be sqrt3, not sqrt 13

maym0Re97
 2 years ago
Best ResponseYou've already chosen the best response.2lol and it should be 13=x^2, not 13=x. I hate the equation thing.

Life
 2 years ago
Best ResponseYou've already chosen the best response.0lol so what i did was correct right?

maym0Re97
 2 years ago
Best ResponseYou've already chosen the best response.2Uhh you did the right thing, you just did it wrong. You go the wrong answer from Pyth. Theorem by yeah you're supposed to use that and then put it over 4.

maym0Re97
 2 years ago
Best ResponseYou've already chosen the best response.2So the final answer you got SHOULD be \[\sin=\sqrt{13}/4\]

Life
 2 years ago
Best ResponseYou've already chosen the best response.0i have a (squared) and c(squared) which means im looking for b (squared) i solved and got 9 +b(squared)=16, subtracted on both sides by 9 and got b2 = 7, not 5 my mistake, where did u get 13 from?

maym0Re97
 2 years ago
Best ResponseYou've already chosen the best response.2Aiiight. The thing is, your side length isn't 3, it's the sqrt of 3. So sqrt of 3 squared is 3. So then you take 16, which is 4 sqared, and subtract 3 from that, giving you 13. Then you end up with 13 = x squared. Take the square root of both sides, and you get square root of 13. Put that over 4 (hypotenuse) for your final answer.

Life
 2 years ago
Best ResponseYou've already chosen the best response.0ughh didnt see that, thanks lol !
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.