Question

find the value of (m+1/m)^2 if m^2+1/m^2=18

Answer 1

We use identity here
then , we know that (a+b)^2=a^2+2ab+b^2
(m+1/m)^2=m^2+2×m×1/m+1/m^2
: m^2+2+1/m^2
And m^2+1/m^2=18
so we add 2 in this equation to find the answer
and 18+2=20
so,clearly the answer (m+1/m)^2=20

Answer 2

(a+b)^2=a^2+b^2+2ab
(m+1/m)^2=m^2+1/m^2+2*m*1/m
(m+1/m)^2=18+2
(m+1/m)^2=20