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(4,1) and (2,3) find the equation of the line passing through the given points. write in function notation.f(x)=

User Koustav
by
2.7k points

1 Answer

17 votes
17 votes

Step 1. We label the points to Find the slope of the line.

The points we have are (4,1) and (2,3), we label them as follows:


\begin{gathered} x_1=4 \\ y_1=1 \\ x_2=2 \\ y_2=3 \end{gathered}

Step 2. Use the slope formula to find the slope "m":


m=(y_2-y_1)/(x_2-x_1)

Substituting our values:


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

Solving the operations:


\begin{gathered} m=(2)/(-2) \\ m=-1 \end{gathered}

Step 3. Now that we have the slope, we use the point-slope equation to find the equation of the line.

The point-slope equation is:


y-y_1=m(x-x_1)

Substituting the values of m, x1, and y1:


y-1=-1(x-4)

now we solve this equation for y by using the distributive property on the right side of the equation:


y-1=-x+4

Add 1 to both sides:


\begin{gathered} y=-x+4+1 \\ y=-x+5 \end{gathered}

Step 4. Change to function notation.

To do this, we change "y" for "f(x)":


f(x)=-x+5

Answer:


f(x)=-x+5

User Soe
by
2.3k points
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