Monday, 1 April 2013

Vedic (Partial Fraction)

Funny Vedic Partial Fraction

$latex E = \frac {2x+1}{x^2 -5x +6} = \frac {2x+1}{(x-3)(x-2)}$

$latex E = \frac {A}{x-3}+ \frac{B}{x-2}$

By quick LOOK:

x =3 => $latex A =\frac {2x+1}{x-2} = 7$
x =2 => $latex B = \frac {2x+1}{x-3}= -5$

=> $latex E = \frac {7}{x-3} - \frac{5}{x-2}$

3P in Research

By Prof C.N. Yang (Nobel Prize Physics)

Perception - grasp the problem with intuition and good vision.

Persistent - keep trying, never give up.

Power - to overcome difficulties.

Hairy Ball Theorem

'Hairy Ball Theorem' (Topology)
1. "You can't comb the hairs on a coconut."
2. "There exists a calm point on earth where there is no wind."
Both 1 & 2  are 'Hairy Ball Theorem'.
If we have a ball with hairs sticking out from each point on it, then impossible to comb the hairs flat with a continuous movement without leaving at least one hair sticking up vertically (typically, at the center of a swirl). Not applicable to doughnut.

=> Wind pattern:

Ball = Earth

Combed down hairs = wind

Length of hairs = wind's force

=> there must be a place on Earth where there is no wind at all.


Vedic (Factorize)

Vedic Sutras:
[s1]: proportionally
[s2]: first by first and last by last

Example 1: E= 2x² + 7x +6

Split 7x = 3x+4x
First ratio of coefficient (2x²+3x) -> 2:3
Last ratio of coefficient (4x+6) -> 4:6=2:3
=> 1st factor = (2x+3)

2nd factor:
2x²/(2x) +6/(3)= (x+2)

=> E = (2x+3).(x+2)

Example 2: Factorize E(x, y, z) = x²+xy-2y²+2xz -5yz-3z²

1. Let z = 0
E'= x²+xy-2y² = (x+2y)(x-y)

2. Let y=0
E'= x²+2xz-3z² = (x+3z)(x-z)

=> E(x, y, z) = (x+2y+3z)(x-y-z)

Example 3:  P(x, y, z) = 3x² + 7xy + 2y² +11xz + 7yz + 6z² + 14x + 8y + 14z + 8

1. Eliminate y=z=0, retain x:

P = 3x²+14x+8= (x+4)(3x+2)

2. Eliminate x=z=0, retain y:

P = 2y²+8y+8 = (2y+4)(y+2)

3. Eliminate x=y=0, retain z:

P = 6z²+14z+8 =(3z+4)(2z+2)

=> P =(x+2y+3z+4).(3x+y+2z+2)

Euler: V- E + R = 2

1. Euler wrote to Goldbach @1750, "it astonishes me these properties have not been noticed by anyone else."

Euler's Polyhedron formula:

V- E + R = 2

Remember trick: “VERsion 2”
V= Vertices, E= Edges, R= Regions (or Faces)
Note: = 0 (instead of 2) for torus doughnut

2. Euler proved it 1 year later: intuition leads to discovery, then prove it by logic.

Example:
Football: Vertices=60, Edges E=90, Region R=32 faces (12 pentagons, 20 hexagons):
V- E + R = 60 - 90 + 32 = 2

[caption id="" align="alignright" width="300"]A football (or soccer ball) icon. A football (or soccer ball) icon. (Photo credit: Wikipedia)[/caption]

Vedic (Multiply)

Vedic Math & 16 Sutras

[s2]: All from 9 and the last from 10
[s3a]: Vertically and
[s3b]: Cross-wise

Example: 872 x 997 = Y ?

Apply [s2]: (8-9) =-1 , (7-9)= -2 , last (2-10) = -8
872 -> [-128]

[s2]: (9-9) = 0 & (9-9)=0 & last (7-10)=-3
997 -> [-003]

Arrange in 2 vertical columns as:
872 -> [-128]
997 -> [-003]

[s3a]: (Vertically):
[-128] x [-003] =384

[s3b]: (Cross-wise):
872 + [-003] = 869
=> Y = 869,384

Now, Quick Demo : Calculate 892,763 x 999,998 = Y

892,763 [-107,267]
999,998 [-2]
=> Y= 892,761,214,534

Hypotenuse

Hypotenuse
[Greek: Stretch Against]

Pythagoras was a visiting scholar in Egypt where he saw the pyramid workers used a rope construction tool. The closed rope had 3 knots separated at distance apart in ratio 3:4:5. When it was 'stretch against' on 3 poles formed a right-angled triangle.