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

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

Hi,

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

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 .. " ???

Wisdom is a tree which grows in the heart and fruits on the tongue

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

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

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).

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

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

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

Wisdom is a tree which grows in the heart and fruits on the tongue

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

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

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

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

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

it's

y= 1 +4x right?

Wisdom is a tree which grows in the heart and fruits on the tongue

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

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

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?

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

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

I know it's -1/4

what after that?

Wisdom is a tree which grows in the heart and fruits on the tongue

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

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

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
?

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

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

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

Wisdom is a tree which grows in the heart and fruits on the tongue

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

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

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

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

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

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

Wisdom is a tree which grows in the heart and fruits on the tongue

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

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

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

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