Question

Find the value of cos(-480°)

Answer 1

Step-by-step explanation:

Cos(-480)°

=Cos(-120°) because 360° is period of Cos

=Cos(120°) because cos(-x)=cos(x)

=Cos(90°-(-30°))

=Sin(-30°) Relation between sin and cos.

=-Sin(30°) because sin(-x)=-sin(x).

=-1/2

Answer 2

$\huge\sf\underline\red{Answer\:⟹}$

$\cos( - 480)$

$\cos( - 480 + 360) = \cos( - 120)$

As per the relationship between sin and cos the answer is :-

⟹ $\frac{1}{2}$