How do you graph the linear function f(x)=-x+4?

Jul 28, 2018

See a solution process below:

Explanation:

First, solve for two points which solve the function and plot these points:

First Point: For $x = 0$

$f \left(0\right) = - 0 + 4$

$f \left(0\right) = 4$ or $\left(0 , 4\right)$

Second Point: For $x = 4$

$f \left(4\right) = - 4 + 4$

$f \left(4\right) = 0$ or $\left(4 , 0\right)$

We can next plot the two points on the coordinate plane:

graph{(x^2+(y-4)^2-0.075)((x-4)^2+y^2-0.075)=0 [-20, 20, -10, 10]}

Now, we can draw a straight line through the two points to graph the line:

graph{(y+x-4)(x^2+(y-4)^2-0.075)((x-4)^2+y^2-0.075)=0 [-20, 20, -10, 10]}

Jul 28, 2018

$\text{see explanation}$

Explanation:

$\text{one way is to find the intercepts, that is where the graph}$
$\text{crosses the x and y axes}$

• " let x = 0, in the equation for y-intercept"

• " let y = 0, in the equation for x-intercept"

$x = 0 \Rightarrow y = 4 \leftarrow \textcolor{red}{\text{y-intercept}}$

$y = 0 \Rightarrow - x + 4 = 0 \Rightarrow x = 4 \leftarrow \textcolor{red}{\text{x-intercept}}$

$\text{Plot the points "(0,4)" and } \left(4 , 0\right)$

$\text{Draw a straight line through them for graph}$
graph{(y+x-4)((x-0)^2+(y-4)^2-0.04)((x-4)^2+(y-0)^2-0.04)=0 [-10, 10, -5, 5]}