Allieeslabae one year ago 12. What is the equation of the line perpendicular to the line y = x – 2 that passes through the point (4,3)? y = –4/9 x – 2 y = 9/4 x + 6 y = – 9/4 x + 12 y = – 9/4 x – 12

1. anonymous

Hi

2. Allieeslabae

Hey do you know how to solve?

3. anonymous

4. anonymous

To find the the perpendicular line of y = x – 2, first we should start with the slope. The slope of the first equation is x. The slope of an equation perpendicular to the original will have the opposite reciprocal of the original slope. So we take the reciprical of x which is 1/x. The opposite (or negative) of 1/x would be -1/x. Make sense so far?

5. Allieeslabae

Okay so slope is x1 x1/ y1 y2 right?

6. anonymous

Could you explain where you got that answer from?

7. Allieeslabae

Thats how you find the slope right? Sorry I meant (x1, y1) and (x 2, y 2)

8. anonymous

That is how you would find the slope when given to pairs of coordinates. For example, if you were given the coordinates (3,4) and (1,2) $\frac{ y2-y1 }{ x2-x1 } \rightarrow \frac{ 4-2 }{ 3-1 } \rightarrow \frac{ 2 }{ 2 } =1$ But to find the slope perpendicular to the original slope, you don't have to use the formula.

9. Allieeslabae

Okay im confused wht do i use then?

10. anonymous

It's just what I said earlier "the opposite reciprocal". That's it. :)

11. Allieeslabae

Okay thanks you. Ill try that!

12. anonymous

So you know how I got -1/x right?

13. Allieeslabae

nope, but I have to go to my tutor, Ill catch her up on what you told me! Thanks though!

14. anonymous

You're welcome. And good luck. :)

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