Final Answer
Step-by-step Solution
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Starting from the right-hand side (RHS) of the identity
Applying the tangent identity: $\displaystyle\tan\left(\theta\right)=\frac{\sin\left(\theta\right)}{\cos\left(\theta\right)}$
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$1+\tan\left(x\right)\tan\left(y\right)$
Learn how to solve trigonometric identities problems step by step online. Prove the trigonometric identity cos(x-y)/(cos(x)cos(y))=1+tan(x)tan(y). Starting from the right-hand side (RHS) of the identity. Applying the tangent identity: \displaystyle\tan\left(\theta\right)=\frac{\sin\left(\theta\right)}{\cos\left(\theta\right)}. Applying the tangent identity: \displaystyle\tan\left(\theta\right)=\frac{\sin\left(\theta\right)}{\cos\left(\theta\right)}. Multiplying fractions \frac{\sin\left(x\right)}{\cos\left(x\right)} \times \frac{\sin\left(y\right)}{\cos\left(y\right)}.