AM-GM Form of a Quadratic

Rarely Tested

AM-GM Form of a Quadratic

## Formula

For $a>0$:

$$ax^2+bx+c=a\left(x+\frac{b}{2a}\right)^2+\frac{4ac-b^2}{4a}$$

Therefore:

$$ax^2+bx+c\ge\frac{4ac-b^2}{4a}$$

## Conditions / Special Cases

Equality occurs at:

$$x=-\frac{b}{2a}$$

## Usage

- Used to find minimum values directly by completing the square.

Question 1

Let $$\alpha, \beta$$ be the distinct roots of the equation $$x^2 - (t^2 - 5t + 6)x + 1 = 0, t \in \mathbb{R}$$ and $$a_n = \alpha^n + \beta^n$$. Then the minimum value of $$\frac{a_{2023} + a_{2025}}{a_{2024}}$$ is

Question 2

The number of real solutions of the equation $$e^{4x} + 4e^{3x} - 58e^{2x} + 4e^x + 1 = 0$$ is ______

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