Use the Fact That the Trigonometric Functions Are Periodic to Find

question 276

Multiple Choice

Use the fact that the trigonometric functions are periodic to find the exact value of the expression. Do not use a calculator.
- $\cot 390 ^ { \circ }$

• A) \(\frac { \sqrt { 3 } } { 3 }\)
• B) \(\sqrt { 3 }\)
• C) \(- \frac { \sqrt { 3 } } { 3 }\)
• D) \(- \sqrt { 3 }\)

---

Definitions:

Effective Rate

The actual interest rate earned or paid on an investment, loan, or other financial product, taking into account the effect of compounding.

Ordinary Interest

A method for calculating interest based on a 360-day year.

360-Day Year

A 360-day year is an accounting practice that treats each month as having 30 days, simplifying interest calculations in the financial industry.

Total Amount

The aggregate sum resulting from the addition of numbers, amounts, objects, etc.