Find-the-value-of-x-3-1-x-3-when-x-1-x-5-

Question Number 87033 by Zainal Arifin last updated on 02/Apr/20

Find the value of x^{3} + \frac{1}{x^{3}}, when

x + \frac{1}{x} = 5

Answered by redmiiuser last updated on 02/Apr/20

{(x + \frac{1}{x})}^{3} = 125

\Rightarrow x^{3} + \frac{1}{x^{3}} + 3 (x + \frac{1}{x}) = 125

x^{3} + \frac{1}{x^{3}} = 125 - 15 = 110

Commented by Zainal Arifin last updated on 02/Apr/20

thank you sir

Commented by redmiiuser last updated on 02/Apr/20

w e l c o m e