Chapter 9: Q. 9.89 (page 930)

Find the intercepts of the parabola whose function is $f (x) = x^{2} + 2 x - 8$ .

Short Answer

Expert verified

The y-intercept is the point (0, −8) .
The x-intercepts are the points $(- 4, 0) a n d (2, 0)$

Step by step solution

Step 1. Given Information

The parabola whose function is $f (x) = x^{2} + 2 x - 8$

We have to find the intercepts of the parabola.

Step 2. Solve

To find the y-intercept, let x = 0 and solve for f (x) .

$f (x) = x^{2} + 2 x - 8 f (0) = {(0)}^{2} + 2 (0) - 8 f (0) = - 8$

When x = 0 , then f (0) = −8 .

The y-intercept is the point (0, −8) .

To find the x-intercept, let f (x) = 0 and solve for x .

localid="1646151346632" $f (x) = x^{2} + 2 x - 8 0 = x^{2} + 2 x - 8$

Solve by factoring:

$0 = x^{2} + 2 x - 8 0 = (x + 4) (x - 2) 0 = x + 4; 0 = x - 2 - 4 = x; 2 = x$

When $f (x) = 0$ , then $x = - 4 o r x = 2$ .

The x-intercepts are the points $(- 4, 0) a n d (2, 0)$

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Find the intercepts of the parabola whose function is $f (x) = x^{2} + 2 x - 8$ .

Short Answer

Step by step solution

Step 1. Given Information

Step 2. Solve

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Find the intercepts of the parabola whose function is f(x)=x2+2x−8.

Short Answer

Step by step solution

Step 1. Given Information

Step 2. Solve

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Math Textbooks

Theoretical and Mathematical Physics

Discrete Mathematics

Pure Maths

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Decision Maths

Mechanics Maths

Study anywhere. Anytime. Across all devices.

Find the intercepts of the parabola whose function is $f (x) = x^{2} + 2 x - 8$ .