Prove the Identity $$\frac { \cos ( x - y ) } { \cos ( x + y ) } = \frac { 1 + \tan x \tan y } { 1 - \tan x \tan y }$$

question 207

Essay

Prove the identity.
- $$\frac { \cos ( x - y ) } { \cos ( x + y ) } = \frac { 1 + \tan x \tan y } { 1 - \tan x \tan y }$$

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Definitions:

Silence

The absence of sound or the act of refraining from speaking; in legal contexts, it can imply consent or acceptance under certain conditions.

Acceptance

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Forbearance To Act

Refers to a legal principle involving the deliberate abstention from enforcing a right.

Contractual Agreement

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