- #1
Daniel McKinley
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Solving the cubic equation x^3 + 6x = 20 by using formula gives
(10+ sqrt(108))^1/3 - (-10 + sqrt(108))^1/3
How do you show that this comes out exactly 2? No calculators allowed.
Tried cubing the expression and tried using the Difference of Cubes formula.
Homework Statement
Solving the cubic equation x^3 + 6x = 20 by using formula gives
(10+ sqrt(108))^1/3 - (-10 + sqrt(108))^1/3
How do you show that this comes out exactly 2? No calculators allowed.
Homework Equations
The Attempt at a Solution
Tried cubing the expression and tried using the Difference of Cubes formula.