Question

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Answer 1

Can you find the slope of line y + 5x = 1 ??

Answer 2

5

Answer 3

How can you tell me ??

Answer 4

Firstly you should write this equation in y = mx + b form. here m is the slope..

Answer 5

y = 5x+

Answer 6

How do you find b?

Answer 7

How ??

y + 5x = 1

Here subtract 5x from both the sides and tell me what did you get ??

Answer 8

y = 1/5x

Answer 9

I am saying to subtract and not divide...

Answer 10

y= -4

Answer 11

Hey man..

y + 5x = 1

Here subtract 5x from both the sides :

y + 5x - 5x = 1 - 5x

Or : y = 1 - 5x (you cannot subtract 1 and 5x as they are unlike terms)..

Answer 12

So, finally you will get :

y = -5x + 1

Answer 13

oh I see but then what???

Answer 14

Here, now tell me what is the slope ??

Compare it with : y = mx + c and tell me what is m here in y = -5x + 1 ??

Answer 15

-5

Answer 16

Yep..

So, the line y + 5x = 1 has slope of -5..

Now tell me what can you say about the slope perpendicular to it??

Answer 17

5 is perpendicular to -5?

Answer 18

No..

Here one property you must remember :

If two lines are perpendicular, then their slopes are negative reciprocals of each other....

Answer 19

So, if one line has slope as \(m_1\) then other line will have slope of \(-\frac{1}{m_1}\)

Answer 20

Getting ??

Answer 21

yeah but how are 2 lines reciprocal of each other if it's not a fraction?

Answer 22

Not two lines..

We are talking about their slopes and not the line...

Answer 23

If two lines are perpendicular to each other then :

Answer 24

Two lines are like this and their slope is negative reciprocal of each other..

Slope is nothing but an angle which line makes with x axis..