Simplifying trig (sin and cos) expression with identities I was working on a trig exercise and I'm not exactly sure how to simplify these expressions. I know the identities are needed to solve the problem but I've never seen angles like these before:
$\cos(\frac{4\pi}{9})$
and
$\sin(\frac{\pi}{55})$
These angles are in radians
I much prefer degrees to radians, so let's do the conversion! $\frac{4}{9} \cdot pi=80^\circ$. pi radians is equal to 180 degrees.
So we would like to find cos 80 degrees. You can use your calculator to solve that one.
sin(pi/55) is similar.
Hope this helped!
These angles are in radians
I much prefer degrees to radians, so let's do the conversion! $\frac{4}{9} \cdot pi=80^\circ$. pi radians is equal to 180 degrees.
So we would like to find cos 80 degrees. You can use your calculator to solve that one.
sin(pi/55) is similar.
Hope this helped!