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if x is a positive acute angle and cos x = radical 3/4, what is the exact value of sin x?
 one year ago
 one year ago
if x is a positive acute angle and cos x = radical 3/4, what is the exact value of sin x?
 one year ago
 one year ago

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maym0Re97Best 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)
 one year ago

maym0Re97Best ResponseYou've already chosen the best response.2
dw:1352794508956:dw
 one year ago

LifeBest 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?
 one year ago

LifeBest 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
 one year ago

maym0Re97Best ResponseYou've already chosen the best response.2
Hrm. Ok. Uhhh what are all the choices?
 one year ago

LifeBest ResponseYou've already chosen the best response.0
sqrt 3/5, sqrt 13/4, 3/5, 4/5
 one year ago

hartnnBest ResponseYou've already chosen the best response.0
alternative way: sin^2 x + cos^2 x = 1
 one year ago

maym0Re97Best 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.
 one year ago

maym0Re97Best ResponseYou've already chosen the best response.2
Woops for the first equation it should be sqrt3, not sqrt 13
 one year ago

maym0Re97Best ResponseYou've already chosen the best response.2
lol and it should be 13=x^2, not 13=x. I hate the equation thing.
 one year ago

LifeBest ResponseYou've already chosen the best response.0
lol so what i did was correct right?
 one year ago

maym0Re97Best 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.
 one year ago

maym0Re97Best ResponseYou've already chosen the best response.2
So the final answer you got SHOULD be \[\sin=\sqrt{13}/4\]
 one year ago

LifeBest 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?
 one year ago

maym0Re97Best 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.
 one year ago

LifeBest ResponseYou've already chosen the best response.0
ughh didnt see that, thanks lol !
 one year ago
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