If y = 3 - √8, find the value of y + 1/y.
Show answer & explanation
Correct answer: D
Explanation
Given:
y = 3 − √8
By the formula:
(a − b)(a + b) = a² − b²
1/y = 1/(3 − √8)
= (3 + √8) / [(3 − √8)(3 + √8)]
= (3 + √8) / (9 − 8)
= 3 + √8
y + 1/y = (3 − √8) + (3 + √8) = 6