/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 78 (a) find the discriminant. (b)... [FREE SOLUTION] | 91Ó°ÊÓ

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(a) find the discriminant. (b) use the discriminant to determine whether the trinomial is prime. $$ 1 x^{2}+8 x+12 $$

Short Answer

Expert verified
The discriminant is 16. The trinomial is not prime, as it can be factored into two linear binomials.

Step by step solution

01

- Write Down the Quadratic Equation

The given quadratic equation is: 1x^2 + 8x + 12 = 0
02

- Identify Coefficients

Compare the quadratic equation to the standard form \(ax^2 + bx + c = 0\). Here, \(a = 1\), \(b = 8\), and \(c = 12\).
03

- Calculate the Discriminant

The discriminant \(\Delta\) is given by the formula \(\Delta = b^2 - 4ac\)Using the identified coefficients, $$\Delta = 8^2 - 4(1)(12) = 64 - 48 = 16$$
04

- Determine the Nature of the Roots

The discriminant value \(\Delta = 16\) is positive. A positive discriminant indicates that the quadratic equation has two distinct real roots. Therefore, the trinomial can be factored into the product of two linear binomials.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Quadratic Equation
A quadratic equation is a polynomial equation of the second degree. This means it has the general form ewline ewline $$ax^2 + bx + c = 0$$ewline ewline where:
  • \(a\) is the coefficient of \(x^2\)
  • \(b\) is the coefficient of \(x\)
  • \(c\) is the constant term.
ewline ewline It's essential to recognize the standard form because it helps in identifying coefficients for further calculations, such as finding the discriminant.
Discriminant
The discriminant is a value that can be calculated from the coefficients of a quadratic equation. It is given by the formula: ewline ewline $$\triangle = b^2 - 4ac$$ ewline ewline The discriminant helps you determine the nature of the roots of the quadratic equation. By plugging in the identified coefficients (\(a = 1\), \(b = 8\), \(c = 12\)) into the formula, you get: ewline ewline $$\triangle = 8​^2 - 4(1)(12) = 64 - 48 = 16.$$ewline ewline A positive discriminant (\(\triangle > 0\)) indicates the equation has two distinct real roots.
Factoring Trinomials
Factoring trinomials involves turning the quadratic equation into a product of two binomials. For the equation ewline ewline $$x^2 + 8x + 12 = 0$$ewline ewline you check if it can be written as: ewline ewline $$(x + m)(x + n) = 0$$ewline ewline You'll find such \(m\) and \(n\) that:
  • m + n = b = 8
  • m * n = c = 12
ewline ewline In this case, \(m = 6\) and \(n = 2\) work because \(6 + 2 = 8\) and \(6 * 2 = 12\). So, the quadratic trinomial \(x^2 + 8x + 12\) can be factored as \((x + 6)(x + 2)\), showing it is not prime.
Real Roots
Real roots of a quadratic equation are the values of \(x\) that satisfy the equation \(ax^2 + bx + c = 0\). Using the quadratic formula \((x = \frac{-b \frac{plus or minus}{-b \frac{minus}{minus}ewline ewline Using the quadratic formula $$x= \frac{- b \frac{plus or minus} \frac{\frac{plus \frac{plus}-4ac}{ -2a}$$ ,ewline ewline these roots can be found: ewline ewline In the given example: $$ Δ = 8^2-4(1)(12) = 16$$,ewline ewline leading to: $$ (\frac{-8\frac{+4}{+4} \frac{ \frac{roots+6}{2} = -2$$,ewline ewline Since Δ is positive, the roots are distinct and real, confirmed by solving \)(x+6)(x+{0}$ instead.ewline ewline Therefore, the quadratic equation has two distinct real roots values.

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