Question

Write an equation of the line containing the specified point and perpendicular to the indicated line
(4, −2), x = 1

Answer 1

http://bit.ly/lMbO9w

x=1 is a vertical line. The perpendicular line must be horizontal, of the form y=c, where c is a constant. if it must pass through (4,-2), the equation must be y = -2.

Answer 2

this is what my instructor wrote to the other student with the same problem...The slope is not correct. x = 1 is a vertical line so the line perpendicular to it is a horizontal line. The slope of a horizontal line is 0.

she wrote y=1x-2

Answer 3

so is that sayin the same thing? that y=-2?
i dont get it

Answer 4

did you look at the link? It shows the two lines and the point.

Answer 5

oh no let me look

Answer 6

i only see a blank graph

Answer 7

there's no red line and blue line? and blue point?

Answer 8

no

Answer 9

OK. Anyway. what do you not understand about my explanation? It seems to mesh with what your instructor is saying...

Answer 10

well i dont know how to write the equation. is it y=-2? and what were the steps to get there?

Answer 11

it's all in my explanation. your original line is x = 1, which is a vertical line, parallel to the y axis, one unit away. so the perpendicular line must be horizontal. horizontal lines have zero slope. if you use the "y = mx + b" equation, and substitute "0" for the slope (m), you get "y = 0x + b" or "y = b". Meaning y = a constant. If you want this line to pass through the point (4,-2), then the constant has to be equal to the y coordinate of the point, or -2. This means the equation must be y = -2.

Answer 12

it's more intuitive if you plot the x=1 and the point on some graph paper.

Answer 13

so if x=1 and y=-2 how is the slope 0?

Answer 14

slope is change in y over change in x. in the equation "y = -2", take two points on the line and calculate the slope with (y1 - y0) / (x1 - x0). You will get the answer zero. or use the "y = mx + b" equation, where m is slope. In the equation "y = -2", m equals zero.

Answer 15

by definition, a horizontal line has slope of zero because there is no change in y. it is a constant.

Answer 16

the slope of x=1 is really undefined. normally you can take the negative reciprocal of a line's slope to get the slope of the perpendicular, EXCEPT with vertical / horizontal, which you must treat as special cases to avoid division by zero.

Answer 17

have you had an epiphany? :-)

Answer 18

ok i think i got it..lol thanks a bunch hope to see ya on my next problem..lol i have my final due by sunday and Lord willing I pass and am done with math..oh wait..i still have intemediate algebra to do!! arrgggg

Answer 19

Lord has nothing to do with it. Believe in yourself! :-)

Answer 20

I can do all things through Christ who strengthens me! Thanks for your help and have a great night!