Question

use an addition or subtraction formula to find the exact value of sin (-5pi/12)

Answer 1

\(\bf -\cfrac{5}{12}\implies
\begin{cases}
\cfrac{\cancel{ 4 }}{\cancel{ 12 }}-\cfrac{\cancel{ 9 }}{\cancel{ 12 }}
\\ \quad \\

\end{cases}\qquad thus
\\ \quad \\
sin\left(-\cfrac{5\pi}{12}\right) \iff sin\left(\cfrac{\pi}{3}-\cfrac{3\pi}{4}\right)\)

Answer 2

hmm

Answer 3

\(\bf -\cfrac{5}{12}\implies
\begin{cases}
\cfrac{\cancel{ 4 }}{\cancel{ 12 }}-\cfrac{\cancel{ 9 }}{\cancel{ 12 }}
\\ \quad \\
\bf \cfrac{1}{3}-\cfrac{3}{4}
\end{cases}\qquad thus
\\ \quad \\
sin\left(-\cfrac{5\pi}{12}\right) \iff sin\left(\cfrac{\pi}{3}-\cfrac{3\pi}{4}\right)\)