@above
i have posted the same solution somewhere else :P
3sinθ-4cosθ=5,3cosθ+4sinθ=?(plz ans this question in a way that i can understand becoz i am a student of class 10)
32sin2x+42cos2x-24sinxcosx=25(squaring)
9(1-cos2x)+16(1-sin2x)-24sinxcosx=25
9+16-(16sin2x+9sin2x+24 sinxcosx)=25
(3cosx+4sinx)2=0
3cosx+4sinx=0
(used x in place of theta)