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#51 Re: Euler Avenue » Limit » 2013-06-16 16:33:48
In projective space there are 2 points at infinity in any direction,since 2 lines intersect in one point and a parallel line intersects both points at infinity,the two points are considered same,thus in case of real projective line infinity and nagetive infinity are the same points and the limit is simply infinity(or minus infinity,doesn't matters cause they're same)
#52 Re: Euler Avenue » Limit » 2013-06-16 13:06:34
The limit would also exist,if it was one sided limit.
#53 Re: Euler Avenue » Limit » 2013-06-16 04:20:33
The second limit does not exist,it would exist if absolute value was used.
#54 Re: This is Cool » Heron's formula without Trig » 2013-06-16 04:17:10
I know this proof,this proof is used in my text book.So can anyone post the proof using trig
#55 Help Me ! » Cross-ratio » 2013-06-14 16:08:45
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How can the cross ratio theorem be proved using ceva's theorem?(i know the proof using trigonometry)
#56 Re: Introductions » SPEM Life » 2013-06-14 03:05:41
Hi phanthanhtom,
welcome to the forum
#57 Re: Science HQ » Science » 2013-06-13 13:26:43
I think science and mathematics are different studies.But science needs maths,though maths doesn't need science.In that sense science is part of mathematics.
#58 Help Me ! » Reciprocation » 2013-06-13 03:35:41
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Given a circle (x-1)^2+(y+1)^2=16 and a point (5,6),what will be the reciprocation line of this point?
#59 Re: Introductions » Hello World » 2013-06-10 18:29:59
Hi,philandy,welcome to the forum
#60 Re: Help Me ! » Conics » 2013-06-09 13:57:30
That is some proof ! I think i'm going to lose my hair thinking about it. But it is an interesting proof at least now i know how the equation comes
#61 Re: Help Me ! » Another geometry proof » 2013-06-09 00:45:51
Hm, can you prove that it will tend to the area as n goes to infinity.
my textbook uses the fact that as n tends to infinity sum of the triangles' base equals to circumference.I'd love to prove it but i'm busy cause my exams have started...
#62 Re: Help Me ! » Conics » 2013-06-09 00:30:31
Found a link it doesn't use algebra-http://xahlee.info/SpecialPlaneCurves_d … ction.html [the link doesn't prove theta is constant for any point 
]
#63 Re: Dark Discussions at Cafe Infinity » By 2024 we will have the 8 billionth baby » 2013-06-09 00:16:25
Whoever it is,I'm sure he/she won't be please to know that he is so late
#64 Re: Help Me ! » Another geometry proof » 2013-06-08 23:14:01
I discovered another proof,the angle standing on a diameter is right,so the angles standing on both side of diameter are right and equal.and equal angles in a circle are stand on similar amd equal arc (congruent arcs).so,the arcs on both side of diameters are equal and it follows the sides are equal in area.
#65 Re: Help Me ! » Another geometry proof » 2013-06-08 17:32:33
Sorry,i didn't find it in the net,i kinda discovered it.
#66 Science HQ » Electron configuration » 2013-06-07 20:39:49
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What is the electron configuration of molybdenum?
#67 Re: Help Me ! » Conics » 2013-06-06 20:39:44
How?
#68 Re: Help Me ! » Factoring Quadratics » 2013-06-06 15:21:00
2x^2+7x+3
=2x^2+6x+x+3
=2x(x+3)+1(x+3)
=(2x+1)(x+3)
#69 Re: Science HQ » Earth » 2013-06-06 13:59:32
Earth may not be based on god or goddess,but it's hindi and bangla name(prithibi) is based on a goddess.
#70 Re: Help Me ! » Conics » 2013-06-06 13:09:57
Sorry,bob but those links prove sum of distance property,not the property i want
#71 Help Me ! » Conics » 2013-06-06 05:20:58
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- Replies: 24
How do you prove that the ratio of a conic section's points' distance from focus and distance from directrix is constant using dandelin spheres?
#72 Re: Help Me ! » Rates of change (conical vessel) » 2013-06-06 02:05:08
Thanks
#73 Re: Help Me ! » Rates of change (conical vessel) » 2013-06-05 23:35:55
Ok.in that case shouldn't dV/dt be a function in terms of t,not h?
#74 Re: Help Me ! » Rates of change (conical vessel) » 2013-06-05 19:38:18
I am confused,since (i) wants rate depending on depth.so we should calculate dv/dh at h=5(which is 25π).correct me if i'm wrong.
#75 Re: Puzzles and Games » Black and White Hats » 2013-06-05 17:17:52
Hi,golchhanmohit,this is a famous riddle,i derived the answer like this-if the guy in the back saw 2 white hat he would know what his hat was. Knowing this fact if the guy in the middle saw a white hat he would know what his hat was.since both of them didn't know what their hat was the hat in the front must be black.