can two lines be perpendicular and parallel at the same time?

Hannibal lecter · 2018-02-03 01:56:17

Hi,

if not...then what is mean the following ? :-

Find equations for the lines through the point (1,5) that are parallel to and perpendicular to the lines the equation y + 4x =7

if the answer is not how can that be " that are parallel to and perpendicular to .. " ???

zetafunc · 2018-02-03 02:01:37

No, you need to find two lines: one which is parallel to y = 4x + 7, and one which is perpendicular to it, each of which pass through (1,5).

Hannibal lecter · 2018-02-03 05:38:25

how can that be in a graph drawing
I know the slop is 1/4

zetafunc · 2018-02-03 06:15:40

Let's start with finding the parallel line through (1,5).

Can you write down a line which is parallel to y = 4x + 7?

Hannibal lecter · 2018-02-03 06:56:19

it's

y= 1 +4x right?

zetafunc · 2018-02-03 07:59:28

Correct! And you can check your answer by substituting x = 1 into your answer to get y = 5.

Now for the perpendicular line passing through (1,5). The line y = 4x + 7 has a gradient of 4. What is the gradient of the perpendicular line?

Hannibal lecter · 2018-02-03 11:26:58

I know it's -1/4

what after that?

zetafunc · 2018-02-03 20:42:40

Yes, so if the perpendicular line has a gradient of , then the line must be of the form . Given that the line passes through , can you find the value of ?

Hannibal lecter · 2018-02-03 22:58:05

I think It's -1/-4 which gives 1/4 positive not negative I think my answer was not correct

so the line is y=0.25x + 4.75

zetafunc · 2018-02-03 23:05:47

No, it's -1/4: the gradient of a line and the gradient of the line perpendicular to it must multiply to make -1.

Hannibal lecter · 2018-02-04 00:22:43

sorry but the orignal line was y = -4x + 7 the slop not positive I'm talking about this case

but thanks anyway I solved all the question about that field

zetafunc · 2018-02-04 00:56:51

Ah, I see -- my apologies, I misread the original equation. In that case, you are completely correct.

Math Is Fun Forum

#1 2018-02-03 01:56:17

can two lines be perpendicular and parallel at the same time?

#2 2018-02-03 02:01:37

Re: can two lines be perpendicular and parallel at the same time?

#3 2018-02-03 05:38:25

Re: can two lines be perpendicular and parallel at the same time?

#4 2018-02-03 06:15:40

Re: can two lines be perpendicular and parallel at the same time?

#5 2018-02-03 06:56:19

Re: can two lines be perpendicular and parallel at the same time?

#6 2018-02-03 07:59:28

Re: can two lines be perpendicular and parallel at the same time?

#7 2018-02-03 11:26:58

Re: can two lines be perpendicular and parallel at the same time?

#8 2018-02-03 20:42:40

Re: can two lines be perpendicular and parallel at the same time?

#9 2018-02-03 22:58:05

Re: can two lines be perpendicular and parallel at the same time?

#10 2018-02-03 23:05:47

Re: can two lines be perpendicular and parallel at the same time?

#11 2018-02-04 00:22:43

Re: can two lines be perpendicular and parallel at the same time?

#12 2018-02-04 00:56:51

Re: can two lines be perpendicular and parallel at the same time?

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