∵1/cosθ-1/sinθ=1∴(sinθ-cosθ)/sinθcosθ=1∴sinθ-cosθ=sinθcosθ又(sinθ-cosθ)^2=(sinθ)^2-2sinθcosθ+(cosθ)^2=1-2sinθcosθ∴(sinθcosθ)^2=1-2sinθcosθ∴(sinθcosθ)^2+2sinθcosθ-1=0(sin...