Without using a calculator, give the exact trigonometric function value with rational denominator.
-cos 60°
A) $\frac { \sqrt { 2 } } { 2 }$
B) $\frac { \sqrt { 3 } } { 2 }$
C) $\frac { 2 \sqrt { 3 } } { 3 }$
D) $\frac { 1 } { 2 }$

Question

Without using a calculator, give the exact trigonometric function value with rational denominator.
-cos 60° 
A) $\frac { \sqrt { 2 } } { 2 }$
B) $\frac { \sqrt { 3 } } { 2 }$
C) $\frac { 2 \sqrt { 3 } } { 3 }$
D) $\frac { 1 } { 2 }$

Quizplus · Accepted Answer

The cosine of 60 degrees is exactly $\frac{1}{2}$, which is a well-known value from the unit circle and trigonometric functions.

Without Using a Calculator, Give the Exact Trigonometric Function Value 22\frac { \sqrt { 2 } } { 2 }22​​

Without Using a Calculator, Give the Exact Trigonometric Function Value $\frac { \sqrt { 2 } } { 2 }$