Question

If X=(ab)-(ab) then prove that x³+3x=ab-1/ab

Answer 1

Step-by-step explanation:

Let y^3=ab, then x=y-1/y; x^3=y^3-3y^2/y+3y/y^2-1/y^3=y^3-3y+3/y-1/y^3.

3x=3y-3/y; so x^3=y^3-3x-1/y^3 and x^3+3x=y^3-1/y^3=(ab)-1/(ab)