To find the roots of the quadratic function g(x)=−4x2−12x+9, we can use the quadratic formula x=2a−b±b2−4ac, where a=−4, b=−12, and c=9.
Step 1: Identify the Quadratic Function
We are given the quadratic function g(x)=−4x2−12x+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=b2−4ac
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=2a−b±D
we substitute b=−12, D=288, and a=−4:
x=−812±288
Calculating the square root:
288=16.9706(rounded to four significant digits)
Thus, the roots are:
x1=−812+16.9706≈−3.6213x2=−812−16.9706≈0.6213
Final Answer
The roots of the quadratic function g(x) are approximately:
x1≈−3.6213x2≈0.6213