Select the correct answer from each drop-down menu.

[tex]\[
\cos \left(420^{\circ}\right) = \quad \_ \_ \_ \_
\][/tex]

[tex]\[
\sin \left(450^{\circ}\right) = \quad \_ \_ \_ \_
\][/tex]

Options:
- [tex]\(\frac{1}{2}\)[/tex]
- -1
- -[tex]\(\frac{1}{2}\)[/tex]
- 1



Answer :

To determine the values of the trigonometric functions given in the question, let's go through a step-by-step explanation.

1. Calculate [tex]\(\cos(420^\circ)\)[/tex]:
- First, notice that 420 degrees is more than 360 degrees. To bring it within the standard range of 0 to 360 degrees, subtract 360 degrees from 420 degrees:
[tex]\[ 420^\circ - 360^\circ = 60^\circ \][/tex]
- So, [tex]\(\cos(420^\circ) = \cos(60^\circ)\)[/tex].
- The value of [tex]\(\cos(60^\circ)\)[/tex] is [tex]\(\frac{1}{2}\)[/tex].

2. Calculate [tex]\(\sin(450^\circ)\)[/tex]:
- Similarly, 450 degrees is more than 360 degrees. To bring it within the standard range, subtract 360 degrees from 450 degrees:
[tex]\[ 450^\circ - 360^\circ = 90^\circ \][/tex]
- So, [tex]\(\sin(450^\circ) = \sin(90^\circ)\)[/tex].
- The value of [tex]\(\sin(90^\circ)\)[/tex] is [tex]\(1\)[/tex].

Given these calculations, we can fill in the drop-down menus as follows:
- For [tex]\(\cos(420^\circ)\)[/tex], the correct option is [tex]\(\frac{1}{2}\)[/tex].
- For [tex]\(\sin(450^\circ)\)[/tex], the correct option is [tex]\(1\)[/tex].

Thus, the complete and correct options are:
[tex]\[ \begin{array}{l} \cos \left(420^{\circ}\right)=1 / 2 \vee \\ \sin \left(450^{\circ}\right)=\checkmark \\ 1 / 2 \\ -1 \\ -1 / 2 \\ 1 \\ \end{array} \][/tex]