解:∵sinθ=3/5,θ∈(π/2,π)
∴cosθ=-√(1-sin²θ)=-4/5
==>tanθ=sinθ/cosθ=-3/4
∵tanφ=1/2
∴tan(θ+φ)=(tanθ+tanφ)/(1-tanθtanφ)
=((-3/4)+(1/2))/(1-(-3/4)(1/2))
=-2/11;
tan(θ-φ)=(tanθ-tanφ)/(1+tanθtanφ)
=((-3/4)-(1/2))/(1+(-3/4)(1/2))
=-2。.