Use the given function value(s), and trigonometric identities (including the cofunction identities), to find the indicated trigonometric functions.
sin 30° = $\frac { 1 } { 2 }$ , cos 30° = $\frac { \sqrt { 3 } } { 2 }$
sin 60° and cos 60°
A) sin 60° = 2 and cos 60° = $\frac { 1 } { 2 }$
B) sin 60° = $\sqrt { 3 }$ and cos 60° = $\frac { 1 } { 2 }$
C) sin 60° = $\frac { \sqrt { 3 } } { 2 }$ and cos 60° = $\sqrt { 2 }$
D) sin 60° = $\frac { \sqrt { 3 } } { 2 }$ and cos 60° = $\frac { 1 } { 2 }$
E) sin 60° = $\frac { \sqrt { 3 } } { 2 }$ and cos 60° = 2

Question

Use the given function value(s), and trigonometric identities (including the cofunction identities), to find the indicated trigonometric functions.  
sin 30° = $\frac { 1 } { 2 }$ , cos 30° = $\frac { \sqrt { 3 } } { 2 }$  
 sin 60° and cos 60°
A) sin 60° = 2 and cos 60° = $\frac { 1 } { 2 }$
B) sin 60° = $\sqrt { 3 }$ and cos 60° = $\frac { 1 } { 2 }$
C) sin 60° = $\frac { \sqrt { 3 } } { 2 }$ and cos 60° = $\sqrt { 2 }$
D) sin 60° = $\frac { \sqrt { 3 } } { 2 }$ and cos 60° = $\frac { 1 } { 2 }$
E) sin 60° = $\frac { \sqrt { 3 } } { 2 }$ and cos 60° = 2

Quizplus · Accepted Answer

The values of sin 60° and cos 60° are derived from the cofunction identities and the given values. Since sin 30° = 1/2, and cos 30° = √3/2, it follows that sin 60° = cos 30° = √3/2 and cos 60° = sin 30° = 1/2, according to the complementary angle relationships in trigonometry.

Use the Given Function Value(s), and Trigonometric Identities (Including the Cofunction