Get the answers you need at Westonci.ca, where our expert community is always ready to help with accurate information. Ask your questions and receive accurate answers from professionals with extensive experience in various fields on our platform. Discover detailed answers to your questions from a wide network of experts on our comprehensive Q&A platform.

Consider these functions:

What is the value of [tex]\( x \)[/tex] when [tex]\( g(h(x)) = 4 \)[/tex]?

A. 0
B. 2
C. 4
D. 5


Sagot :

To determine the value of [tex]\( x \)[/tex] when [tex]\( g(h(x)) = 4 \)[/tex], let's follow these steps:

1. Identify the given functions:
- [tex]\( h(x) = 2x + 1 \)[/tex]
- [tex]\( g(x) = x^2 - 4 \)[/tex]

2. Find [tex]\( g(h(x)) \)[/tex]:
Substitute [tex]\( h(x) \)[/tex] into [tex]\( g(x) \)[/tex]:
[tex]\[ g(h(x)) = g(2x + 1) \][/tex]
Since [tex]\( g(x) = x^2 - 4 \)[/tex], replace [tex]\( x \)[/tex] with [tex]\( 2x + 1 \)[/tex]:
[tex]\[ g(2x + 1) = (2x + 1)^2 - 4 \][/tex]

3. Simplify [tex]\( g(h(x)) \)[/tex]:
Calculate [tex]\( (2x + 1)^2 \)[/tex]:
[tex]\[ (2x + 1)^2 = 4x^2 + 4x + 1 \][/tex]
Subtract 4:
[tex]\[ g(2x + 1) = 4x^2 + 4x + 1 - 4 = 4x^2 + 4x - 3 \][/tex]

4. Set [tex]\( g(h(x)) = 4 \)[/tex] and solve for [tex]\( x \)[/tex]:
[tex]\[ 4x^2 + 4x - 3 = 4 \][/tex]
Rearrange the equation:
[tex]\[ 4x^2 + 4x - 3 - 4 = 0 \][/tex]
Simplify:
[tex]\[ 4x^2 + 4x - 7 = 0 \][/tex]

5. Solve the quadratic equation [tex]\( 4x^2 + 4x - 7 = 0 \)[/tex]:
To solve the quadratic equation, we can use the quadratic formula [tex]\( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \)[/tex], where [tex]\( a = 4 \)[/tex], [tex]\( b = 4 \)[/tex], and [tex]\( c = -7 \)[/tex].

Calculate the discriminant:
[tex]\[ b^2 - 4ac = 4^2 - 4 \cdot 4 \cdot (-7) = 16 + 112 = 128 \][/tex]
Since the discriminant is positive, there are two real solutions:
[tex]\[ x = \frac{-4 \pm \sqrt{128}}{8} = \frac{-4 \pm 8\sqrt{2}}{8} = \frac{-1 \pm 2\sqrt{2}}{2} \][/tex]
Thus, the solutions are:
[tex]\[ x_1 = \frac{-1 + 2\sqrt{2}}{2} \quad \text{and} \quad x_2 = \frac{-1 - 2\sqrt{2}}{2} \][/tex]

6. Evaluate the given options [tex]\( 0, 2, 4, 5 \)[/tex]:
None of the given options (0, 2, 4, 5) correspond to the roots [tex]\( \frac{-1 + 2\sqrt{2}}{2} \)[/tex] or [tex]\( \frac{-1 - 2\sqrt{2}}{2} \)[/tex].

Therefore, given the provided choices and our calculations, none of the options (0, 2, 4, 5) are correct. The actual result is that there is no matching [tex]\( x \)[/tex] value among the given options that satisfies the equation [tex]\( g(h(x)) = 4 \)[/tex]. Hence, the answer is:

```
None
```