Question

Why is it important to calculate the distance between two points on a cartesian coordinate plane?

Answer 1

Answer:

Derived from the Pythagorean Theorem, the distance formula is used to find the distance between two points in the plane. The Pythagorean Theorem,

a

2

+

b

2

=

c

2

, is based on a right triangle where a and b are the lengths of the legs adjacent to the right angle, and c is the length of the hypotenuse. The relationship of sides

|

x

2

−

x

1

|

and

|

y

2

−

y

1

|

to side d is the same as that of sides a and b to side c. We use the absolute value symbol to indicate that the length is a positive number because the absolute value of any number is positive. (For example,

|

−

3

|

=

3

. ) The symbols

|

x

2

−

x

1

|

and

|

y

2

−

y

1

|

indicate that the lengths of the sides of the triangle are positive. To find the length c, take the square root of both sides of the Pythagorean Theorem.

c

2

=

a

2

+

b

2

→

c

=

√

a

2

+

b

2

It follows that the distance formula is given as

d

2

=

(

x

2

−

x

1

)

2

+

(

y

2

−

y

1

)

2

→

d

=

√

(

x

2

−

x

1

)

2

+

(

y

2

−

y

1

)

2

We do not have to use the absolute value symbols in this definition because any number squared is positive.

A GENERAL NOTE: THE DISTANCE FORMULA

Given endpoints

(

x

1

,

y

1

)

and

(

x

2

,

y

2

)

, the distance between two points is given by

d

=

√

(

x

2

−

x

1

)

2

+

(

y

2

−

y

1

)

2

Step-by-step explanation: