Question

find the exact trigonometry value of sin(15),sin(75),cos(-15)and tan(75)

Answer 1

\(\large sin(15)=sin(45-30) \rightarrow \) use difference formula for sine

\(\large sin(75)=sin(45+30) \rightarrow \) use sum formula for sine

\(\large cos(-15)=cos(30-45) \rightarrow \) use difference formula for cosine

\(\large tan(75)=tan(45+30) \rightarrow \) use sum formula for tangent