Question

a) Given that cos x = sqrt3 - 1
find the value of cos 2x in the form a+b sqrt3 where a and b are integers
b)Given that 2 cos(y+30) = sqrt 3 sin(y-30) find the value of k sqrt3

Answer 1

Let ... √3.sin x + cos x = 1.

Then, multiplying both sides by (1/2),

(√3 /2) sin x + (1/2) cos x = 1/2

sin x · cos π/6 + cos x · sin π/6 = sin π/6

sin [ x + (π/6) ] = sin π/6

x + (π/6) = 2nπ ± π/6, ... n is an integer.

Answer 2

that is square root

Answer 3

Thank you the '.' represent multiplication right?