| If x = (5 - sqrt(21))/2 prove that (x ^ 3 + 1/(x ^ 3)) - 5(x ^ 2 + 1/(x ^ 2)) + (x + 1/x) = 0 |

r s Aggarwal exercise 1f chapter 1 maths number system rs agrawal example 14 If x = (5 - sqrt(21))/2 prove that (x ^ 3 + 1/(x ^ 3)) - 5(x ^ 2 + 1/(x ^ 2)) + (x + 1/x) = 0 if x is equal to 5 - root 21/2 prove that x cube + 1 upon x cube minus 5 x square + 1 upon x square+ X + 1 upon x is equal to zero