Find the Exact Value of the Given Expression Using a Sum

question 40

Multiple Choice

Find the exact value of the given expression using a sum or difference formula.
$\cos \frac { 7 \pi } { 12 }$

• A) \(\frac { \sqrt { 3 } - 1 } { 2 \sqrt { 2 } }\)
• B) \(\frac { - \sqrt { 3 } - 1 } { 2 \sqrt { 2 } }\)
• C) \(\frac { \sqrt { 3 } + 1 } { 2 \sqrt { 2 } }\)
• D) \(\frac { - \sqrt { 3 } + 1 } { 2 \sqrt { 2 } }\)

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Definitions:

Vertices

The plural form of vertex, referring to the corners or points where two or more curves, edges, or lines meet.

Asymptotes

Lines that a graph approaches but never reaches, often defining the boundary of its behavior.

Vertices

The corner points where two or more edges meet in a geometric shape or figure; singular form is "vertex."

Ellipse

A plane curve encircling two centers where the total distance from any point on the curve to the two centers remains unchanged.