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tarinbansal

A shortcut to find the equation of line when 2 points lying on that line are given.

Let the 2 points be (p,q) , (r,s)

Let the equation of line be ax-by=c

Then a = (q-s)

b = (p-r)

Find C by putting any one point in the equation.

This method saves your 2-3 steps of that 2 point form and there R also no calculations in this method.

techack

Most of the coordinate geo. shortcuts (given by KAB) can be found in Arihant Coordinate Geometry

v_gurucharan

never mind!!!!!!!!!!!!!!

sankydreams

to find hybridisation of an element in any compound:
calculate the no. of sigma bond that element is making.Add this number to no. of lone pair on that elemnt which arent participating in resonance.
the result gives u the hybridisation number

This idea mite not work in some compounds but most of time its true

nishant_88

Hi everybody I had appeared in JEE 2007 and in the second paper I used the foll shrtcuts:
1)The question that d2x/dy2 equals_______ can be solved by takinsg a three degree function like y=x^3 and then by find out the value of d2x/dy2 and then those of the options given and comparing.
2)The question regarding unit vectors a,b,c such that a+b+c=0 can be solved by taking a=-i, b=1/2i-rt(3)/2j,c=1/2i+rt(3)/2j.
3)The question on mod (z)=1 and z not equal to 1 can be solved using z=i
4)The comprehension on AM,GM and HM can be solved taking two numbers say 8 and 4 and taking n=4 and then finding out the required values.

nishant_88

For any triangle if some expression is to be found then analyse the given conditions and try to use any of the following triangles:
1)A=B=C=60
a=b=c=1

2)A=90,B=C=45
a=rt(2) b=c=1

3)A=90,B=60,C=30
a=2,b=rt(3),c=1

4)A=120,B=C=30

nishant_88

If nos are given to be in HP use 1,1/2,1/3......
For AP use 1,2,3,.....
For GP use 1,2,4,8,............(r>1) or 1,1/2,1/4,1/8,...........(r<1)

When some condition is given then just take some arbitrary values and try to solve.
Say if it is given a+b+c=0, then you can try a=0,b=1,c=-1 or a=1,b=2,c=-3.
In this way a number of tricks can be developed depending on the problem.

v_gurucharan

its gud!!!!!!!!!!!

tarinbansal

It was a good initiative to collect all the good shortcuts at a single place.
Why did it stop?

chimanshu_007

have a lotz.....if u want see my articles....or i can post the links (only in wich shrtcts are there) here...

jssrk

expers plz continue

vishusharma

plz provide links for shorcuts where you have wriitten............

tarinbansal

Go to

http://www.goiit.com/posts/list/0/geometry-ellipse-34919.htm#174532

and see the mothod of jatinroxx.

Not the brute force method but the method given just after that one.

chimanshu_007

@ vishusharma

some of the links

http://www.goiit.com/posts/list/community-shelf-aapke-liye-9086.htm

http://www.goiit.com/posts/list/community-shelf-some-important-shrtcts-binomial-30114.htm

http://www.goiit.com/posts/list/community-shelf-himanshu-for-my-dear-goiitians-shortcuts-26988.htm

http://www.goiit.com/posts/list/community-shelf-himanshu-shortcuts-2-32846.htm

http://www.goiit.com/posts/list/mechanics-formulas-6412.htm

http://www.goiit.com/posts/list/inorganic-chemistry-formulas-again-6628.htm

http://www.goiit.com/posts/list/mechanics-formulasssssssss-6756.htm

http://www.goiit.com/posts/list/algebra-ap-gp-hp-is-nt-difficult-7067.htm

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