tanα=-1/3 tan(β-π/4)=-1/3tan(α+β-π/4)=[tanα+tan(β-π/4)]/[1-tanα·tan(β-π/4)]=[(-1/3)+(-1/3)]/[1-(-1/3)(-1/3)]=-3/4tan(α+β)=tan[(α+β-π/4)+π/4]=[tan(α+β-π/4)+tan(π/4)]/[1-tan(α+β...