Question

solve question number 32 , & 36

Answer 1

Solution. 36)

x^2 +1/x^2 = 7
On adding 2 both sides, we get
=> x^2 +1/x^2 +2 = 7+2
=> x^2 + 1/x^2 + 2 * x * 1/x = 9
=> (x+ 1/x)^2 = 9
=> x + 1/x = 3

Now,
x^3 + 1/^3 = (x+ 1/x) (x^2 + 1/x^2 - x*1/x)
= 3 (7 - 1)
= 3*6
= 18