Question

how do you find the exact value tan(x+y), sinx = (3/5) and secy = (-13/5)

Answer 1

sinx = 3/5 so tanx = 3/4 (assuming x is in QI, but it could also be in QII, in which case tanx = -3/4)

secy = -13/5 so tany = -12/5 (assuming y is in QII, But it could also be in QIII, in which case tany = 12/5)
tan(x+y) = (tanx + tany) / (1 - tanx tany)