2U Maths help (1 Viewer)

[Shazer2]

I have no idea where to start, but would you just got from the origin with the points (2, 0) and (0, 0) to find the gradient and then put the gradient into the point-gradient formula? Not sure.

The second question I have is a simple one, but I can't seem to get it.

I tried using the distance formula and subbing in a, but I couldn't get the right answer. Please help.

 

[RealiseNothing]

Well for #2, the distance between the y values (-1 and 4) is already 5. Hence the x values are the same, so a=3.

 

[Shazer2]

I don't understand that, can you explain it to me a little more? I'm trying my best.

 

[RealiseNothing]

1#

The x intercept at 2 is the co-ordinates (2,0).

So using the two points you know, (2,0) and (3,-4), find the gradient and sub into the point-gradient formula.

 

[Shazer2]

RealiseNothing, I understand that one, thanks

 

[RealiseNothing]

I don't understand that, can you explain it to me a little more? I'm trying my best.

Well we are given the points (a,-1) and (3,4).

We want the distance between these two points to be 5. Now we notice that the y values differ by 5 already right?

This must mean that the point (a,-1) has to be directly under the point (3,4) due to the distance between the y values (or height of the line) already being 5. Hence they both have the same x value.

Draw a diagram to visualise it.

 

[Shazer2]

RealiseNothing, do you know Geogebra? How can I plot it on that?

 

[enoilgam]

I have no idea where to start, but would you just got from the origin with the points (2, 0) and (0, 0) to find the gradient and then put the gradient into the point-gradient formula? Not sure.

A bit rusty, but you use the points (2, 0) and (3,-4) to get a gradient. Then pick one point and sub into the point gradient formula.

Edit: Beaten to the punch by realisenothing.

 

[Shazer2]

A bit rusty, but you use the points (2, 0) and (3,-4) to get a gradient. Then pick one point and sub into the point gradient formula.

Yeah, thanks dude! I got that one covered before, but thanks anyway

 

[RealiseNothing]

RealiseNothing, do you know Geogebra? How can I plot it on that?

Sorry, I'm not really familiar with Geogebra.

Think of it this way.

Graph the two lines y=4 and y=-1, since these are the y values of the two points.

Notice how the distance between these two lines is always 5 if you draw a vertical line straight down? But if you draw a diagonal line, the distance will always be more than 5.

So we know the x values must be the same, since they have to lie on the same vertical line right. So since the first x value is given as 3, 'a' must also be 3.

 

[Sy123]

Less observational solution



Though RealiseNothing's solution is quite smart, man has a good eye.

I know quite alot about Geogebra, that is the graphing program I personally use.

I am pretty sure you can graph it using sliders, by confining the (a,-1) point on the line y=-1
Then drawing the line from this point to the fixed point (3,4)
Making the distance displayable, then using the slider to find that at a=3
Voila! The distance is 5

 

[Shazer2]

That is more what I was looking for, solving by equation. Thanks Sy123 and RealiseNothing.

I have a question, how do you guys get so smart?

 

[RealiseNothing]

That is more what I was looking for, solving by equation. Thanks Sy123 and RealiseNothing.

I have a question, how do you guys get so smart?

Done maths my whole life basically.

You get good at it once you do it enough lol.

 

[Sy123]

There is how you use the sliders in Geogebra, its a great tool.

Also, I can do math adequately enough because I love math. If you practise well enough, and have an affinity with math, then you could be doing 4u with me next year.

 

[Shazer2]

I find it fine when I'm doing it in class, and when I attempt to do homework, I'm screwed.

 

[RealiseNothing]

I find it fine when I'm doing it in class, and when I attempt to do homework, I'm screwed.

The problem isn't your maths ability, but moreso your confidence imo.

When you see a question just think about what you've been taught, don't panic and freak out etc.

Just think it through with a clear mind and you should be fine.

 

[Shazer2]

That is a problem. The wording of problems can sometimes throw me off too.

 

[fishrushed]

Maybe trying breaking down questions into smaller bits because no matter how different the wording of the question is (in exams and textbook questions that is) you can still always break it down to find the little bits of info to piece together and then answer the question asked.
Say for the first question you asked before, you could break it down to:
-Find equation of a line
-x-intercept of 2 (2,0) and goes through (3,4)
from this, you can see: two points are given and you need to find equation, and that should make you think of two point formula

Also in a topic like linear functions, it might help if you sketch out some of the info they have given you.