344,546 views
22 votes
22 votes
If

f

(

x

)

is a linear function,

f

(



2

)

=

2

, and

f

(

2

)

=

0

, find an equation for

f

(

x

)

User Emschorsch
by
3.1k points

1 Answer

8 votes
8 votes

Answer:

f(x) = -1/2x + 1

Explanation:

Remember that f(x) = y

f(-2) = 2 tells you that when x = -2, y = 2 ; So you have point (-2, 2)

f(2) = 0 tells you that when x = 2, y = 0 ; So you have point (2, 0)

Now use the two points to find the slope: Slope = (change in y)/(change in x)

So slope = (0-2)/(2-(-2) = -2/4 = -1/2

Next find "b" using the slope and one point and solve for "b"

y = mx + b slope = -1/2 point (-2, 2)

2 = -1/2(-2) + b

2 = 1 + b

1 = b

Last thing to do: write the equation using slope = -1/2 and b = 1 into y = mx + b

y = -1/2x + 1

User Graham Dumpleton
by
2.9k points