sec2(tan−12)+cosec2(cot−13)=
Let tan−1 2=α⇒tan α=2 and cot−1 3=β⇒cot β=3sec2(tan−12)+cosec2(cot−13)=sec2 α+cosec2 β=1+tan2 α+1+cot2 β=2+(2)2+(3)2=15.