cosα=-4/5sinα=3/5tanα=sinα/cosα=-3/4tan2α=2tanα/[1-(tanα)^2]=2*(-3/4)/[1-9/16]=(-3/2)/[7/16]=-24/7sinβ=12/13cosβ=5/13tanβ=sinβ/cosβ=12/5tan(2α-β)=(tan2α-tanβ)/[(-tan2αtanβ)=(-24/7-1...