Which of the following rules could represent the function shown in the table?
x y
-1 -1
0 1
1 3

f(x) = -2x (A)

f(x) = 2x - 1 (B)

f(x) = 2x + 1 (C)

Respuesta :

ANSWER

The rule is given by the relation,

[tex]y = 2x + 1[/tex]


EXPLANATION

We need to check and see if there is a constant difference between the y-values.


[tex]1 - - 1 = 2 = 3 - 1[/tex]


We can see that, there is a constant difference of 2.

This means that the table represents a linear relationship.


Let the rule be of the form,
[tex]y = mx + c[/tex]


Then the points in the table should satisfy the above rule.


So let us plug in


[tex](0,1)[/tex]


This implies that,


[tex]1 =m (0) + c[/tex]


[tex]1 = 0 + c[/tex]


[tex]c = 1[/tex]



Our rule now becomes,


[tex]y = mx + 1 - - (1)[/tex]


We again plug in another point say, (-1,-1) in to equation (1) to get,



[tex] - 1 = m( - 1) + 1[/tex]

we solve for m now to obtain,

[tex] - m=-1-1[/tex]


[tex] - m = - 2[/tex]


[tex]m = 2[/tex]
We now substitute back in to equation (1) to get

[tex]y = 2x + 1[/tex]

Answer:

Option (C) is correct

f(x) = 2x + 1

Step-by-step explanation:

Slope-intercept form:

The equation of line is given by:

[tex]y=mx+b[/tex]               .....[1]

where, m is the slope and b is the y-intercept.

As per the statement:

Let y = f(x)

Given the table as shown

Let any two points:

(-1, -1) and (0, 1)

Formula for slope(m):

[tex]m = \frac{y_2-y_1}{x_2-x_1}[/tex]

Substitute the given values we have;

[tex]m = \frac{1-(-1)}{0-(-1)}[/tex]

⇒[tex]m = \frac{2}{1} = 2[/tex]

Substitute in [1] we have;

y = 2x+b                ....[2]

Substitute the point (-1, -1) in [2] we have;

-1 = 2(-1)+b

⇒-1 = -2+b

Add 2 to both sides we have;

1 = b

or

b = 1

then, we get the equation:

y =2x+1

or

f(x) = 2x+1

Therefore,  the following rules could represent the function is, f(x) = 2x+1