Are 3x + 8y = 10 and 5x + 5y = 18:
parallel, intersect, or perpendicular
Get Eq. 1 into y = mx + b format:
3x + 8y = 10
8y = -3x + 10
Divide each side by 8
Simplifying, we have:
y = -0.375x + 1.25
Final Answer
Slope = -0.375
Get Eq. 2 into y = mx + b format:
5x + 5y = 18
5y = -5x + 18
Divide each side by 5
Simplifying, we have:
y = -1x + 3.6
Final Answer
Slope = -1
Set EQ1 = EQ2:
-0.375x + 1.25 = -1x + 3.6
-0.375x - -1x = 3.6 - 1.25
+ 0.625x = 2.35
x = 2.35/ + 0.625
x = 3.76
Plug x into equation 1
y = -0.375 * (3.76) + 1.25
y = -1.41 + 1.25
y = -0.16
Our intersection point = (3.76, -0.16)
Calculate the product of the 2 slopes:
Slope 1 * Slope 2 = -0.375 * -1 = 0.375
Perpendicular Check
Since the product of the 2 slopes ≠ -1
The lines are not perpendicular
Line Relation Check
The 2 lines intersect at (3.76, -0.16)
Check if equations are Independent:
Since the slopes are different
The systems are independent
Check if equations are Dependent:
To be dependent
the slopes and y-intercept must be the same.
This is not the case
Check if equations are Inconsistent:
To be inconsistent
The slopes must be the same
Ty-intercepts must different.
This is not the case
Calculate the angle θ
θ is formed by the two lines
tan(θ) = | m2 - m1 |
| 1 + m2m1 |
tan(θ) = | -1 --0.375 |
| 1 + -1 *-0.375 |
tan(θ) = | -0.625 |
| 1 + 0.375 |
tan(θ) = -0.45454545454545
θ = -24.444
Common Core State Standards In This Lesson
How does the 2 Lines Intersection Calculator work?
Free 2 Lines Intersection Calculator - Enter any 2 line equations, and the calculator will determine the following:
* Are the lines parallel?
* Are the lines perpendicular
* Do the lines intersect at some point, and if so, which point?
* Is the system of equations dependent, independent, or inconsistent
This calculator has 2 inputs.
What 3 formulas are used for the 2 Lines Intersection Calculator?
Lines are parallel when they have the same slope.
Lines are perpendicular when they have slopes which are negative reciprocals.
For a line y = mx + b, m is the slope
What 6 concepts are covered in the 2 Lines Intersection Calculator?
- 2 lines intersection
- intersect
- line equation
- parallel
- perpendicular
- two lines which intersect to form a right angle
- slope
- Change in y over change in x