Solving a cubic equation

Published on November 13, 2024

Algebra

The only real solution to the cubic equation a^3 + a^2 - 36 = 0 is a = 3.

Question

Answer

The problem is to solve for in the equation .
We can rewrite the equation as .
This is a cubic equation. We can try integer values of to see if we can find a solution by trial and error.
If , .
If , .
If , .
So, is a solution.
Now we can perform polynomial division to find other solutions. Since is a solution, is a factor of .
So, .
Now we need to solve the quadratic equation .
The discriminant is .
Since the discriminant is negative, the quadratic equation has no real solutions.
Therefore, the only real solution is .
Final Answer: The final answer is