In the Problem, T Is a Real Number and P $\left( - \frac { \sqrt { 39 } } { 8 } , \frac { 5 } { 8 } \right) \quad$

question 313

Multiple Choice

In the problem, t is a real number and P = (x, y) is the point on the unit circle that corresponds to t. Find the exact value of
the indicated trigonometric function of t.
- $\left( - \frac { \sqrt { 39 } } { 8 } , \frac { 5 } { 8 } \right) \quad$ Find $\cos t$

• A)\( - \frac { \sqrt { 39 } } { 5 }\)
• B) \(\frac { 5 } { 8 }\)
• C)\( - \frac { 8 \sqrt { 39 } } { 39 }\)
• D) \(- \frac { \sqrt { 39 } } { 8 }\)

---

Definitions:

Hydrogen

Hydrogen is a chemical element with the symbol H and atomic number 1, known as the lightest element in the periodic table and a primary component of water.

Water

A transparent, tasteless, odorless, and nearly colorless chemical substance that is the main constituent of Earth's streams, lakes, and oceans.

Potassium

A soft, silvery-white metallic element, very reactive, especially in water, and essential for plant and animal life.

KCl

KCl, known as potassium chloride, is a metal halide salt composed of potassium and chlorine, used in medicine, food processing, and as a fertilizer.