Question

What function equation is represented by the graph?

f(x)=−2x−1/2
f(x)=−2x−1
f(x)=−x−2
f(x)=−1/2x−1

Answer 1

B

Explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Calculate m using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (- 1, 1) and (x₂, y₂ ) = (1, - 3) ← 2 points on the line

m =
`(-3-1)/(1+1)` =
`(-4)/(2)` = - 2

Note the line crosses the y- axis at (0, - 1) ⇒ c = - 1

y = - 2x - 1 or

f(x) = - 2x - 1