show that if v(x,y) is a harmonic conjugate for u(x,y), then -u is a harmonic conjugate for v

show that if v(x,y) is a harmonic conjugate for u(x,y), then -u is a harmonic conjugate for v

If v is harmonic conjugate of u, then there is a holomorphic function on somesimply connected domain such that f (z ) such that f (z ) = u + iv .Now defineg (z ) = −i.f (z ) = −iu + vg (z...