Final Answer
Step-by-step Solution
Specify the solving method
Starting from the right-hand side (RHS) of the identity
Learn how to solve problems step by step online.
$\frac{\sin\left(a+b\right)+\sin\left(a-b\right)}{\cos\left(a+b\right)+\cos\left(a-b\right)}$
Learn how to solve problems step by step online. Prove the trigonometric identity tan(a)=(sin(a+b)+sin(a-b))/(cos(a+b)+cos(a-b)). Starting from the right-hand side (RHS) of the identity. Apply the trigonometric identity: \cos\left(a\right)+\cos\left(b\right)=2\cos\left(\frac{a-b}{2}\right)\cos\left(\frac{a+b}{2}\right), where a=a+b and b=a-b. Simplify the product -(a-b). Cancel like terms a and -a.