If [tex]\(\sin 90^{\circ} = 1\)[/tex], then [tex]\(\cos 90^{\circ} =\)[/tex]

A. [tex]\(\frac{1}{2}\)[/tex]

B. [tex]\(0\)[/tex]

C. [tex]\(\frac{\sqrt{2}}{2}\)[/tex]

D. [tex]\(\frac{\sqrt{3}}{2}\)[/tex]

E. [tex]\(1\)[/tex]



Answer :

To determine the value of [tex]\(\cos 90^{\circ}\)[/tex], we can use the trigonometric identities and the unit circle.

1. Trigonometric Identity:
In trigonometry, we know that:
[tex]\[ \sin^2(\theta) + \cos^2(\theta) = 1 \][/tex]
Given that [tex]\(\sin 90^{\circ} = 1\)[/tex], we can substitute this value into the identity:
[tex]\[ 1^2 + \cos^2(90^{\circ}) = 1 \][/tex]
This simplifies to:
[tex]\[ 1 + \cos^2(90^{\circ}) = 1 \][/tex]

2. Solving for [tex]\(\cos 90^{\circ}\)[/tex]:
[tex]\[ \cos^2(90^{\circ}) = 1 - 1 \][/tex]
[tex]\[ \cos^2(90^{\circ}) = 0 \][/tex]
Taking the square root of both sides:
[tex]\[ \cos(90^{\circ}) = 0 \][/tex]

Therefore, the value of [tex]\(\cos 90^{\circ}\)[/tex] is [tex]\(0\)[/tex].

So, in the given options, the correct answer is:
[tex]\[ 0 \][/tex]