Question

pre calc help!

Answer 1

\(\bf \cfrac{7}{12}\implies \cfrac{3}{12}+\cfrac{4}{12}\implies \cfrac{1}{4}+\cfrac{1}{3}\qquad thus
\\ \quad \\
\cfrac{7\pi}{12}\implies \cfrac{1\pi}{4}+\cfrac{1\pi}{3}\implies \cfrac{\pi}{4}+\cfrac{\pi}{3}\qquad thus
\\ \quad \\
sin\left(\frac{7\pi}{12}\right)\implies sin\left(\frac{\pi}{4}+\frac{\pi}{3}\right)\)

Answer 2

and just use your Unit Circle to get the sine and cosine for each :)

Answer 3

so the answer that i marked was correct?

Answer 4

Or you could convert the original angle to degrees, which is much easier in my opinion to deal with! You would then have sin(45 + 60), which are 2 angles with which we are familiar.