MATH 121
LINEAR FUNCTIONS

1. For each of the following pairs of points P1P2, find

a) slope of
b) distance
c) equation of the line passing through P1 and P2
d) midpoint of .

A.     P1(0,1); P2(2, -2)
B.     P1(-5, -4); P2(-1, 7)

2. Write the equation of the line with the given properties.

a) slope of and passing through (6,8)
b) passing through (4,1) and (8,6)
c) passing through (0,1) with a slope of
d) y-intercept of -2 and slope of

3. Write the equation of the line parallel to 2x + 3y - 36 = 0 and passing through (2, -3).

4. Write the equation of the line perpendicular to x - 2y - 4 = 0 and passing through (2, -3).

5. Find the linear function whose graph is parallel to the line segment containing (3, -1) & (4, 4) and has y-intercept of -2.

6. Find the linear function whose graph is perpendicular to the graph of 3x + 4y = 10and passes through (-2, 3).

7. What can you say about the formula for f(x) if f is linear and

a) 3f(x) = f(3x) and (1, -3) is on the graph of f
b) f(2x + 1) = f(2x) + 1
c) f(3) = 2 and f(0) = 5
d) f(x -5) = f(x) -5
e) f(4x + 3) = f(4x) and f(0) = 1
f) f(-1) = 1 and f(-2) = -1

 

ANSWERS Note: All equations for straight lines are written in general form.

1. A. a) m = b)    c) 3x + 2y - 2 = 0    d)
        B. a)     b)    c) 11x - 4y + 39 = 0     d)

2. a) 2x + 3y -36 = 0    b) 5x - 4y -16 = 0    c) x - 8y + 8 = 0    d) x - 2y - 4 = 0

3. 2x + 3y + 5 = 0

4. 2x + y - 1 = 0

5. y = 5x -2

6. 4x -3y + 17 = 0

7. a) y = -3x    b) m = 1; thus y = x + b    c) x + y - 5 = 0    d) m = 1; thus y = x + b   
        e) m = 0; thus y = 1    f) 2x - y + 3 = 0