I think b...............................
<span>We use the Pythagoras Theorem to derive a formula for finding the distance
between two points in 2- and 3- dimensional space.</span>
Let
P<span> = (x 1, y 1) </span>
Q<span> = (x 2, y 2) </span>
be two points on the Cartesian plane
<span>Then
from the Pythagoras Theorem we find that the distance between P and Q is</span>
PQ=((x2-x1)^2+(y2-y1)^2)^0.5
In a
similar way
it can
be proved that if
P<span> = (x 1, y 1, z1) and </span>
Q<span> = (x 2, y 2, z2) are two
points in the 3-dimensional space, </span>
<span>the
distance between P and Q is</span>
PQ=((x2-x1)^2+(y2-y1)^2+(z2-z1)^2)^0.5
<span>
</span>
A fact family is a group of math facts using the same numbers.
Example:
Using the numbers: 5, and 2,
5 ∙ 2 = 10
2 ∙ 5 = 10
10 ÷ 2 = 5
10 ÷ 5 = 2
