Mathematics - 13 August 2006

2006-08-13 08:52:11 · 26 answers · asked by d@dz 5

card a:
4/9/2
3/5/7
8/1/6

card b:
16/2/12
6/10/14
8/18/4


whats in common with these cards?

2006-08-13 08:51:59 · 6 answers · asked by ima lvl 0 pure!!!!!!!!!!!!!!!!!! 1

please show steps so i can understand it

2006-08-13 08:51:39 · 13 answers · asked by Lily 2

i need help on calculus, can anyone give me a good calculus website, anything PLEASE,

2006-08-13 08:48:40 · 11 answers · asked by ...i <3 Xavi... 2

2006-08-13 08:47:39 · 35 answers · asked by mlk35 1

2006-08-13 08:33:44 · 14 answers · asked by David G 1

2006-08-13 08:32:20 · 13 answers · asked by David G 1

1.If the starting temp. is 5 deg. what is the new temp. if it rises 10 deg.
2.what is it if falls 2 deg.
3.what is it if it falls 10 deg.
and what if it rises 12 deg.


The STARTING TEMP IS 5 deg for all of those questions
thanks!

2006-08-13 08:03:10 · 7 answers · asked by Anonymous

I approached this problem by first using the double angle formula.
sin 2x = 2 sin x cos x = cos x

I then divided each side by cos x...
2 sin x = 1

...and then divided each side by 2.
sin x = 1/2

So x = pi/6 or 5*pi/6.

However, when I checked the answers, the solution set also contained pi/2 and 3*pi/2.

I realized then that instead of dividing each side by cos x, I should have subtracted and factored.
2 sin x cos x - cos x = 0
cos x (2 sin x - 1) = 0
cos x = 0 OR 2 sin x - 1 = 0
cos x = 0 OR sin x = 1/2
x = pi/2, 3*pi/2 OR x = pi/6, 5*pi/6

My questions are: Why was my first solution not complete? How can I make it complete? Is there some rule against dividing by cos x (or sin x, tan x, etc)? Or do I need to consider if x is negative?

2006-08-13 07:51:27 · 7 answers · asked by Anonymous

2006-08-13 06:08:09 · 16 answers · asked by Anonymous

f(x)={(3,5),(2,4),(1,7)}
h(x)={3,2),(4,3),(1,6)}

f(h(3))=

2006-08-13 06:06:04 · 4 answers · asked by Sasha 3

why do they change between 'plus' and 'und' when adding. for example:
Eins plus eins ist zwei.
Zwei und eins ist drei.
Drei plus zwei ist fünf.
Zwei und zwei ist vier.
Eins und fünf ist sechs

2006-08-13 05:29:30 · 5 answers · asked by ecko_strong 2

Hi, I was wondering if anyone out there knew of an equation whose answer is a set of all real numbers between 1 and infinity.

2006-08-13 05:29:20 · 3 answers · asked by kaerukaiser 1

As the focus nears the directrix of a parabole what happens to the shape of the parabola

2006-08-13 05:28:31 · 4 answers · asked by Anonymous

2006-08-13 03:45:29 · 5 answers · asked by shalu 1

graph the following equation..
- show all necessary working..

2006-08-13 02:49:24 · 23 answers · asked by daNisha 1

More specifically, I have a table and at the bottom it asks me to calculate the delta of the values.
how do i do this?

2006-08-13 02:42:09 · 19 answers · asked by Azam 2

2006-08-13 02:24:20 · 15 answers · asked by njatc 1

2006-08-13 01:49:53 · 46 answers · asked by Anonymous

1) Prove that no integer in the sequence 11, 111, 1111, 11111... is a perfect square.
2) If n is an odd integer, show that n^4 +4n^2 +11 is of the form 16k.
3) By using the division alogirthm, show
(i) if a and b are odd integers, then 8|(a^2-b^2)
(ii)if p>3 is a prime, then 24|(p^2-1)
(iii) for n>1, prove that n(n+1)(2n+1)/6 is an integer.
4) Find the largest integer n such that n is a divisor of a^5-a for all integers a.

2006-08-13 01:38:17 · 5 answers · asked by edwinvandesar 1

will 7 such gardens produce. these are word problems.

2006-08-13 01:33:37 · 29 answers · asked by Shikhar J 1

Any help much appreciated, first clear answer gets 10 points!

Thanks!

2006-08-13 00:41:55 · 13 answers · asked by HappyPerson 2

Any hints on this one?

I'm starting in a way that seems awkward and roundabout. Let R be a ring. If R is a field, then <0> is a maximal ideal of R; otherwise R contains at least one nonzero element that is not a unit, say x.

Then if R has a unity element, is a proper ideal of R.

Hints on where to go next or how to start over? I know there are lots of theorems on maximal ideals, but I'm (for now) trying to do this by brute force.

2006-08-13 00:35:07 · 4 answers · asked by Anonymous