trig questions attached in img

Question

anonymous · Answer

attachment

jkristia · Answer

which one do you need help with ?

anonymous · Answer

any that you understand ><"

jkristia · Answer

Sorry, I got interrupted.

The first one, what is cos(pi/3) - 1/2

jkristia · Answer

cos(pi/3) = 1/2, so you replace cos(pi/3) with 1/2, so you get
2 * (1/2)^2 - 1 = 0??  => 2 * (1/4) - 1 = ?

jkristia · Answer

same for the next one, sin(3pi/2) = sqrt(3)/2, so replace 'sin' with sqrt(3)/2 and see if the statement is true

jkristia · Answer

anonymous · Answer

perfect! That's what it was called... the unit circle!

jkristia · Answer

yep, very helpful when you have to solve equations involving trig functions

anonymous · Answer

Thank you so much!