Question

If a-1/a = 4, find a²+1/a²​

Answer 1

Step-by-step explanation:

if a-b is given then a^2+b^2= (a-b)^2+2ab

here b = 1/a so a²+1/a² = ( a-1/a)^2 + 2 a(1/a)

= 4^2+ 2 = 18