Question

Sin(x+24) = Cos(y-x) ; Tan(z-24) - Tan(y-z)=0

find: Cos(y-z)

Answer 1

Cos(y-z) = Cos(z-24)

Explanation:

You have two equations in three unknowns, so no solution for the unknowns is possible.

The tangent equation tells you ...

... tan(z -24) = tan(y -z)

... z -24 = y -z . . . . . . take the arctangent

... cos(y -z) = cos(z -24) . . . . take the cosine