If ( 3y + ) = 8 , find the value of ( y2 + ).
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 5 .
3y + 3/y = 8
y + 1/y = 8/3
(y + 1/y)² = y² + 1/y² + 2
⇒ (8/3)² = y² + 1/y² + 2
⇒ 64/9 = y² + 1/y² + 2
⇒ y² + 1/y² = 64/9 − 2 = 64/9 − 18/9 = 46/9 = 5