Evaluate the Trigonometric Function Using Its Period as an Aid $\cos \frac { 23 \pi } { 4 }$

question 82

Multiple Choice

Evaluate the trigonometric function using its period as an aid. $\cos \frac { 23 \pi } { 4 }$

• A) \(\cos \frac { 23 \pi } { 4 } = - \frac { \sqrt { 2 } } { 2 }\)
• B) \(\cos \frac { 23 \pi } { 4 } = - \sqrt { 2 }\)
• C) \(\cos \frac { 23 \pi } { 4 } = \sqrt { 2 }\)
• D) \(\cos \frac { 23 \pi } { 4 } = \frac { \sqrt { 2 } } { 2 }\)
• E) \(\cos \frac { 23 \pi } { 4 } = \infty\)