HELP! find the exact value of the real number y in the equation Y=cos-1(√2/2) and explain how you got this answer please?

Question

jdoe0001 · Answer

are you doing the 30-30-60 rule? or doing trig?

anonymous · Answer

Will you show me both ways? There wasn't a specific way we had to solve it, we just had to solve it.

jdoe0001 · Answer

yes, but before you have to "solve" it, you also need to have it "covered"

jdoe0001 · Answer

so, thus I dunno what section you're doing, for I'd assume your textbook has such

anonymous · Answer

How do I cover it? I have the unit circle and the text book.

jdoe0001 · Answer

.. "cover" as in, you already had a class on it

jdoe0001 · Answer

I mean, what if the teacher decides to ask you how many planets in andromeda or something,  I mean, if it isn't covered... there's no point in testing on it

anonymous · Answer

Oh she has covered it. I just don't understand trig.

jim_thompson5910 · Answer

look at the unit circle and look for points where the x coordinate is sqrt(2)/2

you'll notice that the angle at this point is theta = 45 degrees or pi/4 radians

so depending on which mode you're in, you'll get


Y=cos-1(√2/2) 

Y=45 degrees ... if you want an answer in degrees

or

y = pi/4 radians ... if you want an answer in radians

anonymous · Answer

Oh that is actually pretty simple. Thank you :)

jim_thompson5910 · Answer

yw