The problem asks for the value of $(\alpha^2 + \beta^2 + \gamma^2)$ derived from the solution set of the equation $|x^2 + x - 9| = |x| + |x^2 - 9|$, which is given as $[\alpha, \beta] \cup [\gamma, \infty)$.
We utilize a key property of absolute values: $|a| = |b| + |c|$ holds if and only if $a = b + c$ and the product $b \cdot c \ge 0$.
In this equation, let $a = x^2 + x - 9$, $b = x$, and $c = x^2 - 9$. First, we verify if $a = b + c$: $b + c = x + (x^2 - 9) = x^2 + x - 9$ This matches $a$. Therefore, the original equation $|x^2 + x - 9| = |x| + |x^2 - 9|$ is equivalent to the condition that $b$ and $c$ have the same sign or one/both are zero, meaning $b \cdot c \ge 0$.
The condition simplifies to:
$x \cdot (x^2 - 9) \ge 0$Factorizing the quadratic term gives:
$x(x - 3)(x + 3) \ge 0$The critical points where the expression equals zero are $x = -3$, $x = 0$, and $x = 3$. We test the sign of $x(x - 3)(x + 3)$ in the intervals determined by these points:
The inequality $x(x - 3)(x + 3) \ge 0$ is satisfied when $-3 \le x \le 0$ or $x \ge 3$.
The derived solution set is $[-3, 0] \cup [3, \infty)$.
Comparing this with the given format $[\alpha, \beta] \cup [\gamma, \infty)$, we find:
We now calculate the required value $(\alpha^2 + \beta^2 + \gamma^2)$: $ \alpha^2 + \beta^2 + \gamma^2 = (-3)^2 + (0)^2 + (3)^2 $ $ = 9 + 0 + 9 $ $ = 18 $
Let f and g be functions satisfying $f(x+y) = f(x)f(y), f(1) = 7$ and $g(x+y) = g(xy), g(1) = 1$, for all $x, y \in \mathbb{N}$. If $\sum_{x=1}^{n} \left(\frac{f(x)}{g(x)}\right) = 19607$, then n is equal to :
Let S be the set of the first 11 natural numbers. Then the number of elements in $A = \{B \subseteq S : n(B) \geq 2$ and the product of all elements of B is even is ________.