Clarification of Question by
m4th_g4dg3t-ga
on
01 May 2005 18:27 PDT
I will try to put it here. Let me know if it's not clear.
1. Let n be a natural number and A1,...,An > 0 pairwise different
(Pairwise different is underline = important) positive real numbers.
Show that if ( here it's the problem i mean the character i can't put
it on the web it's like Y but upside down, it's Lamda's sign)
Show that if Y1 (Lamda 1),..., Yn (Lamda n) are such real numbers that the equality
Y(Lamda)1e^((A1)(X))+...+Y(Lamda)ne^(An)(X) = 0
holds true for all x Element (E or belong to) R then Y1 (Lamda
1)=...=Yn(Lamda n) =0
#2
Show that there are infinitely many real numbers x in the interval [0,
(pie/2)] such that both sin x and cos x are rational numbers. (Note: A
real number y is called rational if it can be represented as (m/n) for
some integers m and n)
#3
Show that for any (any is underline = important) real number x E
(element or belong to) [-1,1] and any positive real number B > 0 there
exists a natural number^2 (to the power of 2) n such that
|sin ((square root of 2)*pie*n)-x|< B
In other words, prove that we can make sin((square root of two)*pie*n)
arbitrarily close to x by an appropriate choice of n E (Element or
belong to) N
(Here a little bit -- use the fact that square root of 2 is not a
rational number. A perfect work should also include a proof that
square root of 2 is in fact not a rational number.)
Ok there you go..if you have any questions, let me know ASAP. I will
check my email periodically. Happy Math!!