To find the roots of the quadratic function \( g(x) = -4x^2 - 12x + 9 \), we can use the quadratic formula \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \), where \( a = -4 \), \( b = -12 \), and \( c = 9 \).
Step 1: Identify the Quadratic Function
We are given the quadratic function \( g(x) = -4x^2 - 12x + 9 \). To find the roots of this function, we will use the quadratic formula.
Step 2: Calculate the Discriminant
The discriminant \( D \) is calculated using the formula:
\[
D = b^2 - 4ac
\]
Substituting the values \( a = -4 \), \( b = -12 \), and \( c = 9 \):
\[
D = (-12)^2 - 4(-4)(9) = 144 + 144 = 288
\]
Step 3: Find the Roots
Using the quadratic formula:
\[
x = \frac{-b \pm \sqrt{D}}{2a}
\]
we substitute \( b = -12 \), \( D = 288 \), and \( a = -4 \):
\[
x = \frac{12 \pm \sqrt{288}}{-8}
\]
Calculating the square root:
\[
\sqrt{288} = 16.9706 \quad (\text{rounded to four significant digits})
\]
Thus, the roots are:
\[
x_1 = \frac{12 + 16.9706}{-8} \approx -3.6213
\]
\[
x_2 = \frac{12 - 16.9706}{-8} \approx 0.6213
\]
Final Answer
The roots of the quadratic function \( g(x) \) are approximately:
\[
\boxed{x_1 \approx -3.6213}
\]
\[
\boxed{x_2 \approx 0.6213}
\]