Final Answer
Step-by-step Solution
Specify the solving method
I. Express the LHS in terms of sine and cosine and simplify
Start from the LHS (left-hand side)
Learn how to solve trigonometric identities problems step by step online.
Learn how to solve trigonometric identities problems step by step online. Prove the trigonometric identity sin(10x)/(sin(9x)+sin(x))=cos(5x)/cos(4x). section:I. Express the LHS in terms of sine and cosine and simplify. Start from the LHS (left-hand side). Apply the trigonometric identity: \sin\left(a\right)+\sin\left(b\right)=2\sin\left(\frac{a+b}{2}\right)\cos\left(\frac{a-b}{2}\right), where a=9x and b=x. Combining like terms 9x and x.