Question

Use double angle formulas to evaluate exact measures of

a) sin(π/12)

b) cos(3π/8)

Answer 1

well sin (π/6)= 1/2 , cos (π/6) = (sqrt 3 )/ 2
so sin( π/6 /2) = sqrt [ (1-cos π/6)/2 ]
=sqrt [ (1 - (sqrt 3 )/ 2 ) /2
=sqrt [ (2 - sqrt 3 ) /4 ]
= (1/2) sqrt (2 -sqrt 3) =.259

yes, sin 15 degrees = .259

Answer 2

You do the next one.

Answer 3

why would i ask if i cant do it

Answer 4

thanks though !!

Answer 5

can**