Find the value of `cos15^(@)` with the help of `cos 2A=2cos^(2)A-1`

Find the valueof 2cos45^(@).cos15^(@) :

Find the value of sin (221//2^@) with the help of the value of cos45^@

Find the values of cos 22(1/2)^(@) using the value of cos 45°?

Find the value of cos^-1(cos((3pi)/2))

Using the value of cos 315 ^(@) , find the value of sin 157 ""(1)/(2) ^(@and cos 157 (1)/(2) ""^(@).

Find the value of cos 1^@, cos 2^@ ….. Cos 100^@

Find the value of cos theta. cos 2theta. cos 2^(2)theta . cos 2^(3)theta"……." cos 2^(n-1) theta is

Using the formula cos 2theta = 2 cos^(2)theta - 1 , find the value of cos 30^(@) , it is being given that cos 60^(@) = 1/2