Parallel and Perpendicular Equations
How do you find a line that goes through a given point and is parallel or perpendicular to a given slope? Example: Through (-4,5) parallel to y = -2x - 3.
How do you find a line that goes through a given point and is parallel or perpendicular to a given slope? Example: Through (-4,5) parallel to y = -2x - 3.
Here’s a hint for the example. Have you learned how to determine what a slope is? Have you learned about y-intercepts?
The format of the example is y = mx + b. m is the slope. b is the y-intercept. Although they are shown as positive variables in the format I just gave you, they can be negative numbers. And if you look closely at the example, you will see that both m and b are negative.
Now here is the hint. Write the example in the format I have shown in the previous paragraph. But substitute the same slope as the example for m. Keep b as it is for now. Your new form of the example should be:
y = nx + b, where n = m in the original example. (I know what it is, but I want you to figure it out yourself.)
Now plug in -4 for x and 5 for y:
5 = n*-4 + b
Solve for b:
b = 4n + 5 (Remember that n is the same as m in your original example equation. Use my sample to figure it out.)
Now you have the answer for your example:
y = nx + (4n + 5)
If you were looking for a perpendicular equation for the sample that passes through (-4, 5), n would be equal to -(1/m), where m is the coefficient of x in your example (please let me know if you need to know what a coefficient is).
Thank you very much. This was very helpful.
La publicación no admite más comentarios.