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Forums - General - Quick math help?

Soriku said:

Wait a sec, I think I grasped it. Tell me if I'm correct or not though.

Basically my first equation was y = 5x + 3.

I found a line parallel to that and the answer was y = 5x + 7. So basically I start at 7 and then go up 5 and right 1 for that right?

Then for perpendicular I do the same. I found my answer to be y = 1/5 + 0.8. So I just start at 0.8 and then go up 1, right 5.


i would actually need to see it...but it sounds like u got it

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Soriku said:

Wait a sec, I think I grasped it. Tell me if I'm correct or not though.

Basically my first equation was y = 5x + 3.

I found a line parallel to that and the answer was y = 5x + 7. So basically I start at 7 and then go up 5 and right 1 for that right?

Then for perpendicular I do the same. I found my answer to be y = 1/5 + 0.8. So I just start at 0.8 and then go up 1, right 5.

Well, it's easier to check it out graphing it than saying it. Though, the perpendicular one's slope is MINUS 1/5, the sign is very important

I think the rest is right, though




Yeah, for perpendicular lines you need to take the opposite reciprocal (sometimes called the multiplicative inverse) of the slope and plug it in.

So with a standard equation in slope-intercept form: y=mx+b, a perpendicular line can always be found with the formula y=(-1/m)x+b (but you will have to take into account the special case of an undefined slope when m=0).

For parallel you just plug in the point the line must pass through and solve for b (as you've done above).

As for the linear algebra class, you should be doing something similar to this in that class with interpolating polynomials iirc.



To Each Man, Responsibility

You need to use the point-slope form y-y1 = m(x - x1) to find your new line. So you put the y coordinate in for y1 and the x coordinate in for x1 and solve! The end.



The equations have to be equal, so whatever you do on one side you must do to the other. If you add 5 to one side you add 5 to the other, if you divide by x on one side you divide by x on the other, and so forth.



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i wish I was back in grade 8 math....Those were the days. Back when it didn't take 30 minutes and 3 pages to do one question.



 

 

im_sneaky said:
i wish I was back in grade 8 math....Those were the days. Back when it didn't take 30 minutes and 3 pages to do one question.

What class are you in?

My highest mathematics class was Calculus IV and I never came across such a long problem.



SHMUPGurus said:
Boutros said:
SHMUPGurus said:
Sorry... I'm doing linear algebra at the moment. This simple stuff is fun compared to that! @_@

Whoo! I'm also doing linear algebra. And we both live in Québec! And we both speak french! We might even be in the same class O.o  :P

Oh, the excitement! Je viens de l'Estrie... Ça te dit de quoi? xD

Oui! Mais moi je suis à Québec :( lol



it would be negative 5 because a negative multiplied by a postive is a negeative.... i hated linear equasions



Brawl Code- 3179-6370-3098 Name:Richi   

Mk Code-3480-4494-2675 Name:Richi

 

i always drew a picture....



Brawl Code- 3179-6370-3098 Name:Richi   

Mk Code-3480-4494-2675 Name:Richi