Question

Find the value of y2+1/y2, if y+1/y=12.

Answer 1

Answer:

142

Step-by-step explanation:

y + 1/y = 12

Square both sides.

(y + 1/y)² = 12²

y²+ 1/y² + 2×y×1/y = 144

y²+1/y² = 144 - 2 = 142

Answer 2

Answer:

$142$

Step-by-step explanation:

${y}^{2} + \frac{1}{ {y}^{2} } = {(y + \frac{1}{y} )}^{2} - 2 \\ \\ = {12}^{2} - 2 \\ \\ = 144 - 2 \\ \\ = 142$