If tan x=60/11 and π<x<3π/2 what is cos(x−π)?

Question

If tan x=60/11 and π<x<3π/2 what is cos(x−π) given in fractional form?

Answer 1

Use the formula for the cosine of the difference of two angles.

cos(x-y) = cos(x)cos(y) + sin(x)sin(y)