Q.

If for some α,β;αβ,α+β=8 and sec2(tan1α)+cosec2(cot1β)=36, then α2+β is __________.          [2025]


Ans.

(14)

Given, sec2(tan1α)+cosec2(cot1β)=36

 1+tan2(tan1α)+1+cot2(cot1β)=36

 α2+β2=34

Given, α+β=8          ... (i)

 α2+β2+2αβ=64

 2αβ=30  αβ=15

 βα=(α+β)24αβ          [ βα]

βα=2          ... (ii)

From (i) and (ii), we get

α=3, β=5

 α2+β=9+5=14