Mathematics - 24 June 2007

I know that the answer is pi/8 -1/4ln(2) and that this answer is obtained by means of integration by parts(or maybe not). However, I can't figure out how to arrive at this answer. Can someone please give me some direction? Thanks.

2007-06-24 03:10:47 · 3 answers · asked by Jay J 1

Better yet, if its NOT 20, what's the formula to find out how many it actually takes.

2007-06-24 03:01:13 · 5 answers · asked by cozmik_terra 2

Is there any way to prove this formula other than substituting random numbers?....

2007-06-24 02:51:48 · 5 answers · asked by retrac 1

Multiply: (x + 7)(x – 4)
Solve step by step please!! I got the answer is

x2 + 3x – 28 Is that right?

2007-06-24 02:40:48 · 6 answers · asked by (: 3

solve the following systems of equation by elimination

1. 5x - 2y = 3
y = 2x

2. 3x + 7y = -6
x - 2y = 11

3. 5/x + 3/y = 4
25/x - 2/y = 3

with solutions. thanks.

2007-06-24 02:38:54 · 5 answers · asked by mandyyy 1

im givin link for wich has the figure of the triangle question...plzz open it...
http://www.freewebs.com/dandiwal/triangl...
Question is:D is mid point of side BC of triangle ABC and ray AX is drawn as shown in figure.BM,CN and DG are perpendiculars to AX in M, N, G respectively. Prove that MG=GN...just give da reason...

2007-06-24 02:29:54 · 7 answers · asked by yuv 1

Train leaves station X and travels east 35 km/hr. One hour later, faster train leaves station X and travels east on a parallel track at 40 km/hr. How far from station X will the faster train catch the slower one?

with solution please.

Thanks a lot.

2007-06-24 01:58:02 · 5 answers · asked by mandyyy 1

Onepintcan has taken exception to me for stating that pi is not 22/7. However, using 22/7 in place of pi will produce acceptable results in many cases because it is a useful approximation.

More accurate values of pi can be calculated using various infinite series. However, since it is irrational, one can never get an exact value. I never claimed to have an exact value, but some useful series have been posted here to enable the calculation of good approximations. (much better than 22/7).

One such series is:
4/1 - 4/3 + 4/5 - 4/7 + 7/9 ...... and so on.
This is an infinite series whose sum would reach pi after an infinite number of terms. It is easy to continue the sequence: the numerators are all 4, the denominators are all odd, increasing by 2 each time, and the sign (+/-) alternates.

The more terms you use, the greater the accuracy. However, it does take quite a large number of terms before it achieves an acceptable level of accuracy.

Is this an acceptable answer?

2007-06-24 01:55:45 · 15 answers · asked by Nick J 4

We will call a number N green if 6 x N contains none of the digits 0,1,2,3 and 4. There are two digits such that every green number contains at least one of them. One of these two digits is 1. What is the other?

2007-06-24 00:33:11 · 2 answers · asked by Anonymous