47.2k views
4 votes
How to know which double angle COS formula to substitute in and why. Also if I should leave CSC^2 as it is or if I should change it to 1/SIN^2 to solve

How to know which double angle COS formula to substitute in and why. Also if I should-example-1
User Shylent
by
8.5k points

1 Answer

2 votes

It is given that:-


\begin{gathered} \csc ^2\beta*\cos (2\beta) \\ =(1)/(\sin^2\beta)*(\cos ^2\beta-\sin ^2\beta) \\ =(\cos^2\beta)/(\sin^2\beta)-(\sin ^2\beta)/(\sin ^2\beta) \\ =\cot ^2\beta-1 \end{gathered}

So the correct answer is


\cot ^2\beta-1

User Davvs
by
7.1k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories