We are working on parallel and perpendicular linear functions.
The question I have trouble with is as follows:
Are the lines perpendicular? Parallel? Neither?
9) y = 5x - 7; y = 5x + 8
I know we can use the formula of y = mx + b, but how can I use this formula if I don't know what to substitute?
***Please do not give me the answer to the problem, just where I need to begin on it.***
Thanks!
2006-09-24 14:42:48 · 14 answers · asked by akaplan516 2 in Science & Mathematics ➔ Mathematics
they are parallel, because they have the same slope=5.
2006-09-24 14:46:01 · answer #1 · answered by Meder 2 · 0⤊ 2⤋
Okay, so perhaps you know that when two lines are parallel, then their slopes (m) are equal. When lines are perpendicular, one slope is the negative reciprocal of the other (like 5 and -1/5 are perpendicular). Neither is when neither of those are true.
You don't need to substitute. You're already in the form y=mx+b. Identify the m in each equation, and then compare based on what i told you.
2006-09-24 14:46:54 · answer #2 · answered by need help! 3 · 0⤊ 0⤋
two linear equations are perpendicular when their multiplyication of two slope is -1. for y= 5x -7, slope is +5 according to y=mx+c.
similarly, y= 5x +8 also have slope of +5. so when we multiply these two slopes, we get +25. we do not get -1. so, these two lines are not perpendicular.
compare y = 5x-7 & y = 5x +8,
when these two linear equations do not have y-intercept, that
means y is equal to 5x.
notice that if y= 3x+2 and y =3x +5 are parallel.
that means that we need have same slope. no matter what
y-intercept is.
so y=8x -9 and y=8x +9 are also parallel.
hope u understand.
2006-09-24 16:48:04 · answer #3 · answered by free aung san su kyi forthwith 2 · 0⤊ 0⤋
By looking at 2 formulae,
U can see that the slope, m is 5 for both.
so, the have the same slope, means the 2 lines are parallel.
b is actually the so called shiftment in Y-axis.
That will be a good begining to analyse ur problem =D
2006-09-24 14:50:58 · answer #4 · answered by sam45tun 2 · 0⤊ 1⤋
In the formula y=mx+b the slope of the line is equal to the "m". the "b" tells you the distance the line is up or down on the "y" axis from 0
2006-09-24 14:48:25 · answer #5 · answered by G-Love 1 · 0⤊ 0⤋
parallel. The slops is 5x so on a graph both lines will always move up 5 and over 1. They just have different starting locations.
2006-09-24 14:53:48 · answer #6 · answered by zooba 3 · 0⤊ 1⤋
They have the same slope.... sooooooooooo they are parallel
To be perpendicular to each other the slopes would have to be negative receipricals (such as 2 and -1/2)
2006-09-24 14:52:55 · answer #7 · answered by Anonymous · 0⤊ 1⤋
listen,what is the coefficient of x in the two equations? since they are both 5,this means they are parallel as they have same gradient....however if one was 5 and the other coefficient -5,only then they would have been perpendicular...alright? hope i`ve been a bit helpful to you.
2006-09-25 01:33:35 · answer #8 · answered by sweetfloss8 2 · 0⤊ 0⤋
What does the m term stand for? In this case m is 5. That means, for both equations, that every time x increases by one y increases by 5. That is the direction of both lines. If they have the same direction, what are they then?
2006-09-24 14:48:14 · answer #9 · answered by Anonymous · 0⤊ 0⤋
you know that the slope is "m" in y=mx+b. So what are the slopes of the two functions. If the slopes are similar, what does that tell you. *wink*
email me if you have any questions
2006-09-24 14:49:13 · answer #10 · answered by Devin 2 · 0⤊ 0⤋