AT's Official Homework Help Thread!!

[urbantechie]

I need some help on my Gemetry HW. My mom (can't read my book since she isn't the strongest English reader/speaker) thinks I am taking like Calculus. She told me she took like College classes when she was in 9th grade in Vietnam. Anyways, she totally explained me wrong so I will now ask AT .

Find the Slope(m) and Y-Intercept(b).

First Problem: Y+6=1/2(x-4)


Second Problem: Y-1=4(x-1)


Thanks guys. Please show me how you got the answer, I can't go to the final without knowing how.

Oh yea, I know the slope of the first one is 1/2 and the second 4. Since this is in pretty much slope intercept form, I can tell.

 

[AlphaIVT]

dude, thats so easy, but I'm not going to help you out, typing it all out is a PITA.

 

[zippy]

I'm in Math3H so here it goes...
(ignore the ~'s, they are just there to fill some space so that it doesn't look too weird. )

Y+6=1/2(x-4)
Y+6=1/2x-2
~-6~~~~ -6
Y=1/2x-8

m=1/2, b=8

Y-1=4(x-1)
Y-1=4x-4
~+1~~ +1
Y=4x-3

m=4, b=-3

Basically, you distribute the coefficient (the # outside the "x+/-n&quot over "x+/-n" then +/- the # that is on the "y" side of the equation on both sides so as to isolate "y" and put it into y=mx+b form.

Hope that helps.

 

[AMDJunkie]

Slope-intercept form = y=mx+b, m being slope and b being y-intercept. All you have to do is simplify the equations to that form.

Don't go giving him the answers, zippy. If you can't figure that out on your own, you never will.

 

[urbantechie]

Thanks zippy. Kinda understanding now!

 

[piku]

We are doing this now in Trig... except instead of picking out the slope and intercept we are using exact equations like that to find equations of lines passing through a set of points, whether two lines are perpendicular/parallel, stuff like that.

Actually it is the Analytical Geometry part of the class, not trig itself.

 

[urbantechie]

Ok, one thing I don't understand is on the first prob how you went from x-4 to x-2?

This is probably the only thing I don't understand about slope.

 

[zippy]

No problem urbantechie.

AMD Junkie, it's not like I just flat out gave him the answers, I gave him the written processes and what I was thinking as I did it too. I'm sure he will have plenty more problems similar to these to practice with.

urbantechie, I went from 1/2(x-4) to 1/2x-2. The parentheses indicate multiplication, so you distribute the 1/2 over everything in the parentheses to simplify it, allow you to continue the problem, and eventually get it into y=mx+b (slope/intercept) form.

 

[piku]

urban - he distributed.

 

[urbantechie]

Oic, I just made it complicated in my head!! DOH!! Learned that stuff last year!!

 

[piku]

Think of those problems like this: solve for Y. After you simplify as much as possible, the number next to X is the slope, and the remaining number is the intercept.

 

[zippy]

urbantechie, lol!

It's good it came back to you now and not the day after the test on this unit.

 

[Static911]

Math genius's...LUCKY u....i'm azn, but could NEVER do math well (except in 5th grade when i took first place) AFter that, it was all downhill!!

GL BRO! Ur lucky u got ppl to help u! All i got was a *C* and a yelling!!!!


Static911

 

[urbantechie]

Hey man, I get emotionally beat up by my parent's for anything less than a C.


Another Question!!

A couple other problems say to take these three points (gives me three sets of coordinates) and tells me to find slope of each line to figure out if it is a right trianlge. Am I going to find the slopes of all three lines and use Pythogorean Therom(sp?) to see if it's right or not?

 

[Josh]

Hey, they have sort of program that'll do it for you Check download.com and other search on av.com

 

[urbantechie]

Nah, I need to learn this stuff dude. My parent's will kick my face in if I don't get a B or better in this class!


Zippy, YGPM
Damnit!! He isn't logged on!!

 

[Mday]

y intercept: set x = zero (0), and solve

slope, set y = f(x), differentiate ;-)

 

[Mday]

thanks, urbantechie, i needed the laugh =)

 

[Napalm381]

Why use the Pythagorean theorem? Just check to see if each pair of lines is perpendicular. If a pair is, it's a right triangle.

 

[urbantechie]

MDay, answer my second Question!!!

They give me three sets of coodinates and tell me to find the slope of each line segment. I did, it forms a triangle and now it asks me to figure out weather it is a right triangle or not...do I use Pyth. Theom. and apply it to the slopes to figure out weather it is Right Or not?

Good one Napalm!!

 

[Mday]

it's
y1 - y2
---------- = slope of line defined by (x1,y1), (x2,y2)
x1 - x2

 

[Mday]

remember

slope of f(x) at a = f'(a), if you differentiate ;-)

or it's just

delta Y
-----------
delta X

 

[zippy]

urbantechie, ygpm back.

 

[mAdD INDIAN]

Hmm...I have a trig problem and was wondering if you guys could help me.

"Triangle ABC is inscribed in a semicircle with diameter BC = 10cm. Find the value of angle B that produces the triangle of maximum area."

So the given is that the hypotenuse of the triangle is 10cm.

the formula for the area of the triangle is A = 1/2bh

we let:
b = 10cosØ
h = 10sinØ

so we then get:: A = 1/2 * 10cosØ * 10sinØ

then we find hte derivative for is..which is ::
A' = -10(cos&Oslash(sin&Oslash then we make it equal zero and find Ø. But that's the part I don't get..how do I find Ø?

Can anyone help? Thanks..

 

[urbantechie]

What are you talking about??? I already know that!! LOL!!!

ANYWAYS, I figured it out. Once I have the coodinates, I can get the lengths of the legs and use Pyth. Theorm. on it!!