Chapter 6: Q 6.99 (page 620)

For the function $f (x) = x^{2} - 2 x - 8$
(a) find $x$ when $f (x) = 7$
(b) Find two points that lie on the graph of the function.

Short Answer

Expert verified

The value of $x$ is $- 3, 5$ and the points lying on the graph is $(0, - 8), (1, - 9)$

Step by step solution

Given information

Given the equation $f (x) = x^{2} - 2 x - 8$

Substitute f(x)=7 and calculate the value

Substituting the value, we get

$7 = x^{2} - 2 x - 8 x^{2} - 2 x - 15 = 0 x^{2} - 5 x + 3 x - 15 = 0 x (x - 5) + 3 (x - 5) = 0 (x + 3) (x - 5) = 0 x = - 3, 5$

Calculate the corresponding y values

The values are $(0, - 8), (1, - 9)$ the graph of which is

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For the function $f (x) = x^{2} - 2 x - 8$
(a) find $x$ when $f (x) = 7$
(b) Find two points that lie on the graph of the function.

Short Answer

Step by step solution

Given information

Substitute f(x)=7 and calculate the value

Calculate the corresponding y values

One App. One Place for Learning.

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For the function f(x)=x2-2x-8(a) find xwhenf(x)=7(b) Find two points that lie on the graph of the function.

Short Answer

Step by step solution

Given information

Substitute f(x)=7 and calculate the value

Calculate the corresponding y values

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Math Textbooks

Decision Maths

Mechanics Maths

Calculus

Theoretical and Mathematical Physics

Geometry

Pure Maths

Study anywhere. Anytime. Across all devices.

For the function $f (x) = x^{2} - 2 x - 8$
(a) find $x$ when $f (x) = 7$
(b) Find two points that lie on the graph of the function.