Math 8 Slopes help - Please Help!

[AbhiKap]

Hello, AbhiKap here

Here is a question that I need help on:

"Contains B(-4,2), parallel to FG with F(O,-3) and G(4,-2)"

And then it gives a graph paper to graph it. I started by graphing F and G and connecting it. Then, I graphed the B, but what do I do with it? And is that I did so far correct?

Thanks, Help is appreciated

 

[Deleted member 4993]

Hello, AbhiKap here

Here is a question that I need help on:

"Contains B(-4,2), parallel to FG with F(O,-3) and G(4,-2)"

And then it gives a graph paper to graph it. I started by graphing F and G and connecting it. Then, I graphed the B, but what do I do with it? And is that I did so far correct?

Thanks, Help is appreciated

What is the slope of line FG

Draw a line through B parallel to FG - this line should have same slope as FG.

Are you supposed to solve the problem through graphical method? (i.e. did the instruction say "construct"?).

 

[AbhiKap]

Draw a line through B parallel to FG - this line should have same slope as FG.

Are you supposed to solve the problem through graphical method? (i.e. did the instruction say "construct"?).

What?? I didn't get it.

It says: "Graph the line"

Thanks, Help is appreciated.

 

[JeffM]

What?? I didn't get it.

It says: "Graph the line"

Thanks, Help is appreciated.

Here is the point: two lines that are parallel have the same slope.

Find the equation represented by the first line.

What is its slope?

Find the equation that has the same slope and satisfies point B.

What is that equation?

Graph that second equation.

Three steps. Take them one at a time.

 

[mmm4444bot]

It says: "Graph the line"

"Contains B(-4,2), parallel to FG with F(0,-3) and G(4,-2)"

it gives a graph paper to graph it. I started by graphing F and G and connecting it. Then, I graphed the B, but what do I do with it? And is that I did so far correct?

Yes -- what you have done so far is correct.

Next, do you understand the meaning of "parallel" ?

You need to draw a second line parallel to FG, and the second line must go through point B.

Subhotosh asked you: What is the slope of FG?

Have you learned the slope formula? slope = (y2 - y1)/(x2 - x1)

If you have not yet learned the formula, then please tell us what you already know about slope and parallel lines.

Cheers :cool:

 

[AbhiKap]

Yes -- what you have done so far is correct.

Next, do you understand the meaning of "parallel" ?

You need to draw a second line parallel to FG, and the second line must go through point B.

Subhotosh asked you: What is the slope of FG?

Have you learned the slope formula? slope = (y2 - y1)/(x2 - x1)

If you have not yet learned the formula, then please tell us what you already know about slope and parallel lines.

Cheers :cool:

Yes, I know the slope formula. Also, I know that Parallel lines have the same slope while Perpendicular lines have negative reciprocal slope.

 

[mmm4444bot]

Okay, you understand it -- but what is preventing you from doing it? What exactly are you confused about?

Start at point B. Move same RUN & RISE as FG-slope, and plot a second point. Draw a line through that point and B.

Finished! :cool:

---

EG:

Draw the line through point K that is parallel to line RS.

Point K is at (-11, 4)

The slope of line RS is 5/3

Step1: Interpret slope 5/3 as RISE 5 and RUN 3.

That means the change in y is 5 units and the change in x is 3 units

Step2: Start at point K and RISE 5 units

Step3: Now RUN 3 units

Step4: The new location is (-11+3, 4+5) = (-8, 9). Plot that point L

Step5: Draw line through points K and L



Alternatively, calculate new coordinates directly:

We know change in x is +3, so add 3 to x-coordinate of point K

We know change in y is +5, so add 5 to y-coordinate of point K

New point L has coordinates (-11+3, 4+5) which is (-8, 9)

GENERAL FORM: (oldX + RUN, oldY + RISE) = (newX, newY) on line with slope RISE/RUN through (oldX,oldY)