The distance formula is an algebraic expression used to determine the distance between two points with the coordinates (x1, y1) and (x2, y2).
<span><span>D=<span><span>(<span>x2</span>−<span>x1</span><span>)2</span>+(<span>y2</span>−<span>y1</span><span>)2</span></span><span>−−−−−−−−−−−−−−−−−−</span>√</span></span><span>D=<span>(<span>x2</span>−<span>x1</span><span>)2</span>+(<span>y2</span>−<span>y1</span><span>)2</span></span></span></span>
Example
Find the distance between (-1, 1) and (3, 4).
This problem is solved simply by plugging our x- and y-values into the distance formula:
<span><span>D=<span><span>(3−(−1)<span>)2</span>+(4−1<span>)2</span></span><span>−−−−−−−−−−−−−−−−−−</span>√</span>=</span><span>D=<span>(3−(−1)<span>)2</span>+(4−1<span>)2</span></span>=</span></span>
<span><span>=<span><span>16+9</span><span>−−−−−</span>√</span>=<span>25<span>−−</span>√</span>=5</span><span>=<span>16+9</span>=25=5</span></span>
Sometimes you need to find the point that is exactly between two other points. This middle point is called the "midpoint". By definition, a midpoint of a line segment is the point on that line segment that divides the segment in two congruent segments.
If the end points of a line segment is (x1, y1) and (x2, y2) then the midpoint of the line segment has the coordinates:
<span><span>(<span><span><span>x1</span>+<span>x2</span></span>2</span>,<span><span><span>y1</span>+<span>y2</span></span>2</span>)</span><span><span>(<span><span><span>x1</span>+<span>x2</span></span>2</span>,<span><span><span>y1</span>+<span>y2</span></span>2</span>)</span><span>
</span></span></span>
The standard form of the equation of a circle is (x-h)^2 + (y-k)^2 = r^2, where (h,k) is the center of the circle, (x,y) is a point of the circle, and r is the length of the radius of the circle. When the equation of a circle is written, h,k, and r are numbers, while x and y are still variables. (x-2)^2 + (y-k)^2 = 16 is an example of a circle. The problem gives us two of the three things that a circle has, a point (5,9) and the center (-2,3). We need to find the radius in order to write the equation. We substitute -2 for h, 3 for k, 5 for x, and 9 for y to get (5 - (-2))^2 + (9 - 3)^2 = r^2 We simplify: 49 + 36 = r^2, r^2 = 85. We only need to know r^2 because the equation of a circle has r^2. We now have all the information to write the equation of a circle. (x + 2)^2 + (y - 3)^2 = 85.
Answer:
3 1/6. Hope this helps :)
Answer:
Step-by-step explanation:
PL^2 =7^2 +3^2
PL^2=49+9
PL=
Answer:
C
Step-by-step explanation:
Since this creates a 45-45-90 triangle, we know they are equal since the legs of 45-45-90 triangles are congruent
