If x - 1/x = 6, then x3 - 1/x3 is equal to:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 234
⇒ x - 1/x = 6
⇒ (x - 1/x )3 = 63
⇒ x3 - 1/x3 - 3(x)(1/x)(x - 1/x) = 216
⇒ x3 - 1/x3 - 3(6) = 216
⇒ x3 - 1/x3 = 216 + 18 = 234