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Example Questions
Example Question #101 : Coordinate Plane
Which of the following is the equation of a line between the points and
?
Since you have y-intercept, this is very easy. You merely need to find the slope. Then you can use the form to find one version of the line.
The slope is:
Thus, for the points and
, it is:
Thus, one form of our line is:
If you move the to the left side, you get:
, which is one of your options.
Example Question #102 : Coordinate Plane
What is an equation of the line going through points and
?
If you have two points, you can always use the point-slope form of a line to find your equation. Recall that this is:
You first need to find the slope, though. Recall that this is:
For the points and
, it is:
Thus, you can write the equation using either point:
Now, notice that one of the options is:
This is merely a multiple of the equation we found, so it is fine!
Example Question #272 : Ssat Upper Level Quantitative (Math)
Given the graph of the line below, find the equation of the line.
To solve this question, you could use two points such as (1.2,0) and (0,-4) to calculate the slope which is 10/3 and then read the y-intercept off the graph, which is -4.
Example Question #244 : Geometry
Which line passes through the points (0, 6) and (4, 0)?
y = –3/2 – 3
y = 2/3 + 5
y = 2/3x –6
y = –3/2x + 6
y = 1/5x + 3
y = –3/2x + 6
P1 (0, 6) and P2 (4, 0)
First, calculate the slope: m = rise ÷ run = (y2 – y1)/(x2 – x1), so m = –3/2
Second, plug the slope and one point into the slope-intercept formula:
y = mx + b, so 0 = –3/2(4) + b and b = 6
Thus, y = –3/2x + 6
Example Question #1 : How To Find The Length Of A Line With Distance Formula
Let W and Z be the points of intersection between the parabola whose graph is y = –x² – 2x + 3, and the line whose equation is y = x – 7. What is the length of the line segment WZ?
7
4
4√2
7√2
7√2
First, set the two equations equal to one another.
–x² – 2x + 3 = x – 7
Rearranging gives
x² + 3x – 10 = 0
Factoring gives
(x + 5)(x – 2) = 0
The points of intersection are therefore W(–5, –12) and Z(2, –5)
Using the distance formula gives 7√2
Example Question #2 : How To Find The Length Of A Line With Distance Formula
In an xy-plane, what is the length of a line connecting points at (–2,–3) and (5,6)?
11.4
7.5
9.3
12.5
11.4
Use the distance formula:
D = √((y2 – y1)2 + (x2 – x1)2)
D = √((6 + 3)2 + (5 + 2)2)
D = √((9)2 + (7)2)
D = √(81 + 49)
D = √130
D = 11.4
Example Question #3 : How To Find The Length Of A Line With Distance Formula
What is the distance between points and
, to the nearest tenth?
The distance between points and
is 6.4. Point
is at
. Point
is at
. Putting these points into the distance formula, we have
.
Example Question #4 : How To Find The Length Of A Line With Distance Formula
What is the slope of the line between points and
?
The slope of the line between points and
is
. Point
is at
. Point
is at
. Putting these points into the slope formula, we have
.
Example Question #5 : How To Find The Length Of A Line With Distance Formula
What is the distance between and
?
Let and
and use the distance formula:
. The distance formula is a specific application of the more general Pythagorean Theorem:
.
Example Question #6 : How To Find The Length Of A Line With Distance Formula
What is the distance, in coordinate units, between the points and
in the standard
coordinate plane?
The distance formula is , where
= distance.
Plugging in our values, we get
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