Question

if y2 + 1/y2 = 11, find the value of y - 1/y

Answer 1

Step-by-step explanation:

square of y-1/y = (y-1/y)^2

= y^2 - 2(y)(1/y) + (1/y)^2

= y^2 +1/y^2 -2

= 11 - 2 { given y2 + 1/y2 = 11 }

= 9

Now (y-1/y)^2 = 9

(y-1/y) = √9 = 3

y-1/y = 3