The Math Problem Thread

MM · **Joined:** Thu Feb 15, 2007 11:57 am **Posts:** 3863

The distance formula is

d = √(x₁ − x₂)² + (y₁ − y₂)²

It works because of the pythagorean theorem, I'll put up a drawing.

http://imageflock.com/img/1212444083.bmp

Phred · **Posted:** Mon Jun 02, 2008 7:04 pm

I told you it was easy.

MM · **Joined:** Thu Feb 15, 2007 11:57 am **Posts:** 3863

Yeah.

Find X and C.

(REALLY easy)

Phred · **Posted:** Tue Jun 03, 2008 6:10 pm

X=60 degrees
C=square-root of 29

MM · **Joined:** Thu Feb 15, 2007 11:57 am **Posts:** 3863

Correct.

Do the following lengths make a right triangle?

3, 6, 7

67, 89, 92

439052845, 458904587, 578973453

Phred · **Posted:** Tue Jun 03, 2008 8:19 pm

no

no

I'm not gonna do the third due to sheer calculation. And Lazyness.

MM · **Joined:** Thu Feb 15, 2007 11:57 am **Posts:** 3863

Correct for the first two, but the last one remains unsolved:

Do the following lengths make a right triangle?

439052845, 458904587, 578973453

MM · **Joined:** Thu Feb 15, 2007 11:57 am **Posts:** 3863

Double post and bump, but I feel like the addition of [math] makes it okay.

$f(x) = -x + .0005 * (0.5x - 46)^2 + 21\sqrt{|x + \frac{1}{x + 1}|}$
Find the x and y intercepts, if any.

$f(x) = \frac{3x^2}{x^2-16}$
Find the x and y intercept(s), if any. Find the vertical and horizontal asymptote(s), if any. State the domain and range in interval notation.

X intercept(s): $x = ?$ (and $x = ?$ , if needed)
Y intercept(s): $y = ?$ (and $y = ?$ , if needed)
Vertical asymptote(s): $x = ?$ (and $x = ?$ , if needed)
Horizontal Asymptote(s): $y = ?$ (and $y = ?$ , if needed)
Domain: $(-\infty, ?) \cup (?, ?) \cup (?, \infty)$
Domain: $(-\infty, ?) \cup [?, \infty)$

EDIT: Phred, the answer to your problem is as such:
Year 5, Month 12: Deposit: 2743.37. Salary: 146.41.
(http://officialgms.com/project/math_problem.php)

Phred · **Posted:** Sat Mar 06, 2010 4:04 pm

wow, that dude's fuckin' broke.

MM wrote:

$f(x) = \frac{3x^2}{x^2-16}$
Find the x and y intercept(s), if any. Find the vertical and horizontal asymptote(s), if any. State the domain and range in interval notation.

f(x)=3x^2/(x+4)(x-4)...
so, asymptotes at x=4 and x=-4.
is interval the whole ()[] thing?
If so:
domain: (-infinity,infinity) Except, y'know, 4 and -4.
range: [0,infinity)
intercept at origin. Unless I"m high, which I am.
Be warned, this is first glance, and I haven't done math in forever. So fuckit. I have a feeling it's wrong.

MM · **Joined:** Thu Feb 15, 2007 11:57 am **Posts:** 3863

Asymptotes are correct.
Domain is not correct, write it using the template I had above. Not that hard.

Same for range, but that's not correct anyways. Try graphing it.
Intercepts are at origin, correct.

Given that $\vec{A} = <4, 7, 3>$ and $\vec{B} = <5, 9, 2>$
Evaluate:
$\vec{A} \bullet \vec{B} = ?$ (dot product. result is a scalar)
$\vec{A} \times \vec{B} = ?$ (cross product. result is another vector.)
$normalized \vec{A} = ?$

Jack · **Joined:** Fri Feb 16, 2007 9:10 pm **Posts:** 220

MM wrote:

Asymptotes are correct.
Domain is not correct, write it using the template I had above. Not that hard.

Same for range, but that's not correct anyways. Try graphing it.
Intercepts are at origin, correct.

Given that $\vec{A} = <4, 7, 3>$ and $\vec{B} = <5, 9, 2>$
Evaluate:
$\vec{A} \bullet \vec{B} = ?$ (dot product. result is a scalar)
$\vec{A} \times \vec{B} = ?$ (cross product. result is another vector.)
$normalized \vec{A} = ?$

MM · **Joined:** Thu Feb 15, 2007 11:57 am **Posts:** 3863

I actually got <-13, 7, 1> for the cross product. And a completely different magnitude. Try those again.

Also, the domain/range?

Jack · **Joined:** Fri Feb 16, 2007 9:10 pm **Posts:** 220

Weird. I'm sure that magnitude is right. And the cross product, yeah. I multiplied 3 and 5 to make 14. Weird.

Domain: $(-\infty, -4) \cup (-4, 4) \cup (4, \infty)$
Range: $(-\infty, -3) \cup (0, \infty)$

Solve: log(1*2*3*4...9*10) without a calculator. You are given that log2 = .301, log3 = .477, log7 = .845.
Hint: Show all steps, i.e. the factoring you do.

MM · **Joined:** Thu Feb 15, 2007 11:57 am **Posts:** 3863

log (1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10)
log (2 * 3 * 2 * 2 * 3 * 10 * 7 * 2 * 2 * 2 * 3 * 3 * 10)
log2 + log3 + 2log2 + log3 + log10 + log7 + 3log2 + 2log3 + log10
6log2 + 4log3 + log7 + 2log10
6(.301) + 4(.477) + .845 + 2(1)
1.806 + 1.908 + .845 + 2
|6.559|

------- Merged -------

E - with a calculator, I get log(3 628 800) = 6.55976303 which works.

The Math Problem Thread

Who is online