IIT JEE , AIEEE Forum - Institutes & Courses , Non IIT Institutes - SHORT CUTS 4 AIEEEEEEEEEE/IIT JEE???????????

ganesha1991

The time taken to double and triple the thickness of ice will be in the ratio of
t₁ : t₂ : t₃ = 1² :2² :3²

the time for thickness of ice grpwing from x₁ to x₂ is given by
t =

L [x₂² -x₁² ]/ 2K

L- latent heat of ice

- density of ice
K- conductivity

ganesha1991

when n number of particles are located at the vertices of a regular polygon of n side having side length a and if they start moving heading to each other
they must collide at the centrre of the polygon after the time

t = a / { v [ 1-cos2

/n ] }

v- speed of each particles

bsgdabest

shortcut for integration:
google vedic maths..really helpful to break functions to partial fractions and solving the question orally..u shud be able to find it anywhere..
suppose u want to break f(x)/(x-a)(x-b)(x-c)
where f(x) is a polynomial in x, of degree less than the dr.
u can first write down

A/(x-a) + B/(x-b) + C/(x-c) where A= f(a)/(a-b)(b-c)
B= f(b)/(b-a)(b-c) and so on, u can have many variations of this technique when it is in other forms like f(x)/(x-a)²(x-c) and so on...this was just an example, i am sure u can find more when u google it..hope this helped

ganesha1991

From a point on the ground at distance x from a vertical wall a ball is thrown at an angle 45 it just clears the wall and strikes the ground at a distance y on the other side
then the height of the wall h = xy/x+y

ganesha1991

when a body is allowed to fall freely from a height h₁ and if rebounds to height h₂
then e =

h₂ /h₁

ganesha1991

the momentum transferred to a floor when the ball hits the floor

p = p [1+e] /[1-e]

ganesha1991

EDIT

brainbank

more replies please!!

astrojith

Does anyone have shortcuts regarding Electricity and Optics ?

And yeah, Chemistry too. Desperately in need of it.

sagar90

kal hi mujhe ek shortcut pata chala which is for angle betn the tangents to the circle frm any point p(x,y)
angle =2 tan^-1 a/ square root of s1
where root of s1 is obtained by putting x,y in given eqn and a is d radius.

sagar90

i knw 1 more:
if we r asked to find foci of an ellipse
thn it is S=(+or- root of a^2 - b^2, o)

lakshmis.kvasn

It is useful if we remember results of some problems which may serve as a basic building block for a complex problem. Remembering some limits really helped in one of my tests. And it is important that v read the question paper thoroughly before beginning to answer. It helps us to plan to utilize our time effectively.

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