Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
Life
Group Title
if x is a positive acute angle and cos x = radical 3/4, what is the exact value of sin x?
 2 years ago
 2 years ago
Life Group Title
if x is a positive acute angle and cos x = radical 3/4, what is the exact value of sin x?
 2 years ago
 2 years ago

This Question is Closed

Life Group TitleBest ResponseYou've already chosen the best response.0
dw:1352794320204:dw
 2 years ago

maym0Re97 Group TitleBest ResponseYou've already chosen the best response.2
Mk 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)
 2 years ago

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

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

Life Group TitleBest ResponseYou've already chosen the best response.0
one 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
 2 years ago

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

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

maym0Re97 Group TitleBest ResponseYou've already chosen the best response.2
it's sqrt 13/4
 2 years ago

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

maym0Re97 Group TitleBest ResponseYou've already chosen the best response.2
You 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.
 2 years ago

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

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

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

maym0Re97 Group TitleBest ResponseYou've already chosen the best response.2
Uhh 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.
 2 years ago

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

Life Group TitleBest ResponseYou've already chosen the best response.0
i 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?
 2 years ago

maym0Re97 Group TitleBest ResponseYou've already chosen the best response.2
Aiiight. 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.
 2 years ago

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