Question

select the correct answer from each drop-down menu.
cos(420°) =
sin(450°) =

Explanation:

Step1: Reduce angle modulo 360°

$\cos(420^\circ) = \cos(420^\circ - 360^\circ) = \cos(60^\circ)$

Step2: Evaluate cosine of reduced angle

$\cos(60^\circ) = \frac{1}{2}$

Step3: Reduce angle modulo 360°

$\sin(450^\circ) = \sin(450^\circ - 360^\circ) = \sin(90^\circ)$

Step4: Evaluate sine of reduced angle

$\sin(90^\circ) = 1$

Answer:

1. $\boldsymbol{\frac{1}{2}}$
2. $\boldsymbol{1}$