Find the Exact Value of the Expression Using the Provided $\cos ( s - t )$

question 467

Multiple Choice

Find the exact value of the expression using the provided information.
-Find $\cos ( s - t )$ given that $\cos s = - \frac { 1 } { 6 }$ , with $s$ in quadrant III, and $\cos t = - \frac { 3 } { 5 }$ , with $t$ in quadrant III.

• A) \(\frac { 3 - 4 \sqrt { 37 } } { 30 }\)
• B) \(\frac { 3 - 4 \sqrt { 35 } } { 30 }\)
• C) \(\frac { 3 + 4 \sqrt { 35 } } { 30 }\)
• D) \(\frac { - 3 + 4 \sqrt { 35 } } { 30 }\)

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Definitions:

Subcooling

Term used to describe the additional cooling of A/C refrigerant in the bottom of the condenser after it has changed from vapor to liquid below its freeze point. In physics, this is known as supercooling.

A/C System

A system in vehicles and buildings designed to cool the air, improving comfort for occupants.

Low Pressure

Refers to situations where the pressure within a system or component is below the normal operating level, potentially indicating a problem.

High Pressure

Pertains to a condition where the pressure in a system or container is significantly above atmospheric pressure, often used in hydraulic or pneumatic systems.