### Home > CAAC > Chapter 12 > Lesson 12.4.3 > Problem 12-94

12-94.

If

*f*(−1) = 7 and*f*(3) = 8, and if the graph of*f*(*x*) is a line: Homework Help ✎Graph the line on graph paper.

Find the equation for

*f*(*x*).If

*g*(*x*) is a line that is perpendicular to*f*(*x*), what is its slope?

f(-1) = 7 represents the point (-1, 7).

Graph this point and the point corresponding to f(3) = 8 in order to sketch the line.

Use the y = mx + b format where m = slope (growth) and b = y-intercept (starting point).

Find the growth and substitute one of the coordinates of a point in the problem and solve for b.

A line g(x) that is perpendicular to f(x) has a slope that is the negative reciprocal of the slope of the line f(x).