1. **State the problem:** Given the function $f(x) = 2x^2 + 4$ and the equation $f(x + 2) = 2x^2$, find the value of $x$.
2. **Use the function definition:** We know that $f(x + 2) = 2(x + 2)^2 + 4$ by substituting $x + 2$ into the function.
3. **Set up the equation:** According to the problem, $f(x + 2) = 2x^2$, so
$$2(x + 2)^2 + 4 = 2x^2$$
4. **Expand the square:**
$$(x + 2)^2 = x^2 + 4x + 4$$
So,
$$2(x^2 + 4x + 4) + 4 = 2x^2$$
5. **Distribute and simplify:**
$$2x^2 + 8x + 8 + 4 = 2x^2$$
$$2x^2 + 8x + 12 = 2x^2$$
6. **Subtract $2x^2$ from both sides:**
$$\cancel{2x^2} + 8x + 12 = \cancel{2x^2}$$
$$8x + 12 = 0$$
7. **Solve for $x$:**
$$8x = -12$$
$$x = \frac{-12}{8}$$
8. **Simplify the fraction:**
$$x = \frac{\cancel{-12}^{-3} }{\cancel{8}^2} = -\frac{3}{2}$$
**Final answer:**
$$x = -\frac{3}{2}$$
Function Value Ef22Fb
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.