Question

How do you evaluate `cos ((53 pi) / 6)`?

Answer 1

`-sqrt(3)/2`

Explanation:

`cos((53pi)6)=cos(((48+5)pi)/6)=cos (4pi+5pi/6)=cos (5pi/6)`

`cos (5pi/6)=cos (pi-pi/6)=-cos(pi/6)=-sqrt(3)/2`