Math Forum / Mathematics / Undergraduate Math / May 2005

Here's a problem I contracted during a visit to an alien math group.  Are
there any know cures?
Quadratic irrationals are the roots of quadratic
polynomials with integer (or rational) coefficients.

Okay, I am having trouble with a problem that involves graphing two seperate circles and finding out where they intersect.
Currently I have a 7 radius circle on point ( 10, 0  )
            and a 5 radius circle on point ( 0, 0 )
my equation or whatever it is looks like this:

What is the slope of the secant line joining (2, f(2)) and (3, f(3)) for f(x) = -3x^2 -8? I came up with -45 as the answer, but a fellow student came up with -55. Who's right?

i would like to use mathematica to solve the following equation,
1-1/x^6+x^2=0 with the condition that "x" is real and larger than zero.
may anyone point me to an appropriate  direction to solve it?

Hi, It's been a long time since I have done maths and I have been
presented with this Question at Uni and I could do with some help on how
to go about solving it:
"A company that manufactures computer housings is trying to reduce

Could anyone help me solve these nine problems please? I need help!
1. Solve for x: logv7x+logv7(x-2)=logv724
2. Which of the following sets: N, Z, Q, and I, together compose the set of real numbers?
N and Z together

Can anyone help me solve these nine problems please? I need help!
1. Solve for x: log (lower) 7, x + log (lower) 7 = log (lower) 7, root square (upper) 24
2. Which of the following sets: N, Z, Q, and I, together compose the set of real numbers?
N and Z together

Hi.  I'm working on an limit problem for my math class.  No one has solved it yet.  Please solve it with work and email me the entire solution and work and I will PayPal you $5.  Here's the problem...
lim  sin(3(x+h))-sin(3x)
h->0 -------------------
            h

How would you prove that the image of a bounded set mapped by a bounded
linear transformation is also bounded?

I have 2 questions:
1.I just learned that
sinh(t) = (e^(t) - e^(-t)) / 2
cosh(t) = (e^(t) + e^(-t)) / 2

In triangle ABC,let A' be on BC,B' on CA and C' on AB,and suppose that the cevians AA',BB', and CC' meet at M.Prove that if ABC triangle is similar to A'B'C',then M is the centroid of ABC triangle

I did put this in with my other Thread, but thought it deserves another
topic!
"
One of the first systems dealing with contention based data transmission

Here's a nice problem on triangles and parallelograms that some of you may not have seen in a while.  It used to be popular in the real old (ca. 1910) textbooks, but it still has alot to offer.
ABCD is a parallelogram.  E is the midpoint of DC, and F is the midpoint of AD.  ...

Trigonometry is really giving me troubles . Anyhow , question is related to trigonometry equations
sin x=a only when |a|<=1
First solution is from interval [-PI/2 , PI/2] -> x=arcsin a ;
Since sine function has period 2*PI ,the equation has infinite number of solutions :

Suppose that f(x)=Ax^3+Bx^2+Cx+D with  A=/=0 , and such that
         A+2B+4C+8D < 0 .
It's true that there exists a point x_0, x_0 in (0,1),
such that    f(x_0) < 0  ?