Prove the Identity $$\csc \left( \frac { \pi } { 2 } + u \right) = \sec u$$

question 72

Essay

Prove the identity.
- $$\csc \left( \frac { \pi } { 2 } + u \right) = \sec u$$

Understand the appropriate openings for different types of routine requests.

Distinguish between simple and complex requests and identify when further justification is required.

Recognize the necessity of a specific call to action in the closing of routine request messages.

Understand strategies for developing positive messages and responses to routine requests.