Math Forum / Mathematics / Undergraduate Math / February 2007

I need to simplify
[ln (sec x)] where x=pi/4

I hope this is the right place for my post. My question is about conditional probability. In all the sources I consulted, P(A|B) is undefined if P(B)=0. Then, I don't know how to face problems as the following:
1) A value for a standard normal variable X is generated, until one of ...

I'm having a little bother clearly understanding a proof. Would be grateful
for feedback on my approach and on any tips/suggestions etc from you
knowledgables.
So I'm proving (supposedly) that "a^p ? a (mod p) where p is a prime and a

I've been programming for a while using sine & cosine and just started taking trigonometry and I am trying to make a relation between the two.
Using a graphing calculator, How do you graph a circle using sine & cosine.  I am already familuar with x^2 + y^2 = r^2.

Heya, I'm self-studying physics (and math as well), and I just started into upper-undergrad level classical mechanics. I'm using the second edition of Marion's Classical Dynamics of Particles and Systems, and my god, this is so much harder than it was before. I'm on the easy ...

I have the following recursion and I'd like to compute its closed
form:
Base: T(1,j) = j, 1<=j<=n; T(i,1) = 1, 1 <=i<=m
Recursion: T(i,j) = T(i, j-1) + T(j-1, i) + 1, 2 <=j <=n, 2 <= i <= m

Z1,Z2 are IID nad Z~N(0,1), W=(Z1^2 + Z2^2) / 2 is standard exponentioal?
P(W<w)=P(((Z1^2 + Z2^2) / 2) <w) = P((Z1^2 + Z2^2) <2w)
= P(Z1^2<2w)+P(Z2^2<2w)??
if not then how can we approach this..

Could anyone help?
How to show (m^2+n^2)/(m+n)^2 > (m(m-1) + n(n-1))/((m+n)(m+n-1)) for m,n
positive integers. Thanks for any help.
Tad

I need to show that polynomials of degree n over an integral domain
have at most n zeros. I know this holds true for fields, but without a
field we lose the division algorithm and its corollaries, so how
should i go about proving it?

The problem says "Show by means of differentials that
                               1/(x+dx) = 1/x - dx/x^2
How do I go about it?  Thanks.

Dear Students,
 I am a scientist, providing help for undergrad,
postgrad, distance education and adult students in doing assignments,
theses, projects, dissertations, essays, etc.

Ok, perhaps I should have extended the decimal numbers,   including 1.4142135 & 2.828427) toward [infinity].... then what I stated would have been more correct. If everyone is going to quibble over such small matters then you are going to miss the real gist of all the Col's ...

Can someone find for me the value of dk/dx=0, for
k=x^2/-b+ax/b.

Suppose we have two cartesian graph points in 3-dimension, stated as:
******
z= 0
x= 2

Knowing that A is an uncountable set and P(A) is the power set of A,
we want to prove that

there is no mapping from P(A) to A