Easy Algebra Step-by-Step

176 Easy Algebra Step-by-Step

Step 2. Identify the quadrant in which the point lies.

Because x is positive and y is positive, (1, 6) lies in quadrant I.

c. (−8, −3)

Step 1. Note the signs of x and y.

x is negative and y is negative.

Step 2. Identify the quadrant in which the point lies.

Because x is negative and y is negative, (−8, −3) lies in quadrant III.

d. (−4, 2)

Step 1. Note the signs of x and y.

x is negative and y is positive.

Step 2. Identify the quadrant in which the point lies.

Because x is negative and y is positive, (−4, 2) lies in quadrant II.

Finding the Distance Between Two Points in the Plane

If you have two points in a coordinate plane, you can fi nd the distance

between them using the formula given here.

Distance Between Two Points

The distance d between two points (x 1 , y 1 ) and

(x 2 , y 2 ) in a coordinate plane is given by

Distance = d =

2 2

()xx 21 x +()yyy 21 −y

Problem Find the distance between the points (−1, 4) and (5, −3).

Solution

Step 1. Specify (x 1 , y 1 ) and (x 2 , y 2 ) and identify values for x 1 , y 1 , x 2 , and y 2.

Let (x 1 , y 1 ) = (−1, 4) and (x 2 , y 2 ) = (5, −3). Then x 1 = −1, y 1 = 4, x 2 = 5,

and y 2 = −3.

P

To avoid careless errors when

using the distance formula, enclose

substituted negative values in

parentheses.