Questions: What is the discriminant of the polynomial below?
2x^2 + 5x - 8
A. -59
B. 89
C. 31
D. -39
Transcript text: AA
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Apex Learning
Sem 1
^ 3.6.4 Quiz: The Quadratic Formula
Question 4 of 10
What is the discriminant of the polynomial below?
\[
2 x^{2}+5 x-8
\]
A. -59
B. 89
C. 31
D. -39
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Solution
Solution Steps
To find the discriminant of a quadratic polynomial \( ax^2 + bx + c \), we use the formula \( b^2 - 4ac \). Here, \( a = 2 \), \( b = 5 \), and \( c = -8 \). We will substitute these values into the formula to calculate the discriminant.
Step 1: Identify Coefficients
For the quadratic polynomial \( 2x^2 + 5x - 8 \), we identify the coefficients:
\( a = 2 \)
\( b = 5 \)
\( c = -8 \)
Step 2: Apply the Discriminant Formula
The discriminant \( D \) is calculated using the formula:
\[
D = b^2 - 4ac
\]
Step 3: Substitute Values
Substituting the identified coefficients into the formula:
\[
D = 5^2 - 4 \cdot 2 \cdot (-8)
\]
Step 4: Perform the Calculation
Calculating each part:
\[
D = 25 - (-64) = 25 + 64 = 89
\]
Final Answer
The discriminant of the polynomial \( 2x^2 + 5x - 8 \) is \(\boxed{89}\).