Question

Can someone help me with this please? I don't know how to do this.

Write the equation for the horizontal line that contains point G(-8, 8).

Answer 1

Horizontal lines are of the form y=n where you may have been given a point in the form (m, n). You have such a point G.

Answer 2

keep in mind that a horizontal line is parallel to x axis, and slope is the value of tan of the angle between the x axis and the line

Answer 3

@piscez.in: What do you mean by the slope is the value of tan of the angle between the x-axis and the line? Specifically, what do you mean by the value of tan?

@tcarroll010: Okay, just a moment please.

Answer 4

So it would be something like y = 8 - (-8)?

Answer 5

@fang02 tan value as in tangent value, like sine cosine, tan etc.

Answer 6

Hmm..I do not believe I have learned about the tan value then.

Answer 7

He means that the equation of a line in slope-intercept form, in general is y = mx + b and that here we have "0" slope, so the mx term disappears. So, we have y=b, or in my notation, y=n. You have point (-8, 8) which is the same distance away from the x-axis as the "b" intercept, (0, 8), so you can simplify and use the "n".

Answer 8

@Fang02 oh im sorry hun, well then forget it. But try to roughly draw the line on a paper. Find the y intercept. And you must already be knowing that the slope of horizontal lines( lines parallel to x axis) is always 1

Answer 9

Not y = 8 - (-8). Instead, y=n where n = 8

Answer 10

So, the answer is pretty much y = 8 then?
No need to be sorry pisez.in.

Answer 11

Yes! You got it. Good job! It's just y=8.

Answer 12

Okay, thanks a lot! :) Would you mind helping me with another problem real quick?

Answer 13

sure!

Answer 14

Write an equation in point-slope form of the line through point J(4, 1) with slope -4.

Answer 15

Point-slope form is y2 - y1 over x2 over x1
So, I think it would be:
1 - 4 over something

Answer 16

point-slope form is going to be:\[y - y _{1} = m(x - x _{1})\] Here, y is y and x is x as variables. x1 and y1 are a SPECIFIC point in the form (x1, y1)

Answer 17

(x1, y1) is the point you are given that is (4, 1), so x1 is 4 and y1 is 1.

Answer 18

I think that (x1, y1) would be (-4, 1) right?

Answer 19

Why does the 4 turn positive?

Answer 20

(x1, y1) is the point you are given that is (4, 1), so x1 is 4 and y1 is 1. It's the slope that is -4.

Answer 21

I understand.

Answer 22

So now, just substitute.

Answer 23

y - y1 = m(x - x1)
y - 1 = -4 (4 - 4) ?

Answer 24

Not quite there yet. What happened to "x"? "x" stays as "x" just like "y" stays as "y". You only substitute for y1, x1, and m.

Answer 25

Oh okay. So, y = 1 = -4(x - 4)

Answer 26

You still have a small typo, but you are extremely close now.

Answer 27

Would I put x1 in parenthesis to show that it is positive and is just being subtracted?
y = 1 = -4(x - (4))

Answer 28

You don't have to do that, you can just leave it as y - 1 = -4(x - 4). Notice how after the "y" I changed that from "=" to "-"

Answer 29

Oh okay, I understand now.

Answer 30

Very nice working with you and you will get there. Just keep up the good work!

Answer 31

Thanks! You too! :)