Sunday, August 25, 2013
Sunday, August 11, 2013
How to Solve Quadratic Equation
How to Solve Quadratic Equation
What is the meaning of solving Quadratic Equation?
Answer is quite simple "In sample manner finding the roots of equation"
Now what are roots of quadratic Equations.
Roots are those values of "x" at which the equation is satisfied for e.g.
2x2 -8x + 5 = 0
roots of this equations means those values of x at which this equation is satisfied
let x1 and x2 be those values of x
then when we put these values in equation it must satisfy it
L.H.S=R.H.S
Solving Equation
First we have to find the nature of roots.For this we have to find discriminant
Roots can be real,equal and complex
Following Equation is the genric quadratic equation
ax2+bx + c = 0
Discriminant or D is given by
D = b2- 4ac
If
D > 0 two roots are real
D = 0 roots are equal
D < 0 two roots are complex
For e.g.
Case 1:
for the equation
2x2 -8x + 5 = 0
Compare it with generic quadratic equation ax2+bx + c = 0
a= 2 ,b= -8,c= 5
so D = (-8)2 -4*2*5
= 64 -40
=24
24 >0
s o it has two real roots
Case 2:
Now consider this equation
x2 -2x + 5 = 0
so a= 1,b= -2,c = 5
D= (-2)2 -4*1*5
= 4 -20
= -16
Since -16 <0 font="" nbsp=""> 0>
so D is negative it has two complex roots
Case 3 :
x2 -2x + 1 = 0
a=1,b=-2,c=1
D = (-2)2 -4*1*1
= 4-4
=0
Since D=0 so it has two equal roots
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Tuesday, July 30, 2013
Understanding Quadratic Equations
Iam explaining quadratic equation in most simple way
"Quadratic Equation" consist of two terms Quadratic and Equation
Dictionary meaning of Quadratic means "Of, relating to, or containing quantities of the second degree."
So Quadratic means term containing power of two
Equations means " The act or process of equating or of being equated"
Quadratic Equations means "An equation in which one or more of the terms is squared but raised to no higher power, having the general form ax2 + bx + c = 0, where a, b, and c are constants."
Quad stand for 2 any equation which have highest power of 2 is quadratic equation
For e.g.
5x2 + 6x + 8= 0
2x2 -8x + 5 = 0
Now consider this example
5x2 + 5x +15
Is it a quadratic equation
Not its not a quadratic equation because it is not equating to any thing.
For a quadratic equation it must be eual to something
for e.g.
5x2 + 5x =8
Is it a quadratic equation
Yes it is a quadratic equation
How to solve Quadratic Equation
Before this we should know why we solve and what will we get after solving this equation
Solving a Quadratic equation means getting the values which will satisfy this equation
and those values which satisfy the equations are known as roots.
For a Quadratic equation there can be only two roots possible for a single quadratic equation
Since quad means two so only two roots are possible for a quadratic equation.
Consider this example
let y = x2 + 5x + 6 = 0
we need to solve it or we have to find the roots of this equation.
roots are those values of x at which y = 0
y = x2 + 5x + 6=0
=>x2 + 5x + 6=0
=>x2 + 3x+2x + 6=0
=> x(x+3) +2(x+3) =0
=> (x+3)(x+2)=0
so roots are x= -3 and -2
if we place these roots in equation in place of x we ger
first take x = -3
then LHS (-3) 2 + 5(-3) + 6
9 -15 +6
-6+6
= 0
LHS = RHS
Sunday, June 30, 2013
Multipication on finger tips trick
Every time we see the sign of multiplication we start using the method we were taught in school.
It is time consuming but saves our brain fuel.
But if we use our brain then we can save time
What is Multiplication
Multiplication is addition.
Yes it is.
Consider this example
Multiply 2 by 3
2* 3 .
It means that add 2 three times or add 3 two times
2+2+2 = 6
or
3 + 3 = 6
So if we want to multiply 27 by 39 then it means addition of 27 to 39 time or addition of 39 to 27 term
there are diffrent ways of multiplication we can use depending upon our way of understanding
for e.g.
2 8
×3 5
140
84×
980
use this technique
28 is 20 + 8
35 is 30 + 5
Now first multiply the exterior terms mean that 30 × 20 = 600
then multiply cross term 20 ×5 = 100
30×8 = 240
in last 8 ×5 = 40
final result is addition 28×35= 980
Friday, March 8, 2013
Square of number starting with 5?
In our daily life we use number 5 many times.In this method you will going to learn how to get square of number starting with 5 like 51, 52 53 etc and so on.
51*51=2601
RHS = Square of number at ones place here it is 1*1=1 =>01
LHS = 25 + the number at ones place here its 1 =>(25 + 1)=26
answer is LHS/RHS = 26/01 =>2601
Now
52 * 52 = 2704
RHS =2 * 2 =04
LHS = 25 + 2=27
Answer is 27/04 = 2704
Now
54 * 54 = 2916
RHS = 4 * 4 = 16
LHS =25 + 4 = 29
Answer is 2916
Try to find square of 53 , 55, 56 ,57 etc
Square of number ending with 5?
The most easiest way to get square of number ending with 5.
It is based on Vedic maths.
By using this trick you can get square of any number ending with five within fraction of second
Consider a number
15*15 = . 225
Wondering how its works?
Right hand side it is always 25
LHS = (number) * (number +1)
here it is 1 * (1+1)= 2
so the answer is 2/25 (backslash is for indication only) so we get 225
next number is 25
RHS =25
LHS= 2*(2+1)=>2*3=6
Answer is 625
Similarly
square of 35
3*(3+1)/25
1225
try the square of these number and share the result in Comments
45,55,65,75,85,95
Monday, March 4, 2013
Prime number Check Trick
Prime number check.
Prime numbers are those numbers which are only divisible by
one and itself.
1,35,7,11,13,17 and so on……..
For small numbers it is easy to say whether number is Prime
number or not.
But for large number like 1189 it is quite difficult to check
its prime number test
But here is the trick that can check Prime number test within
fraction of seconds.
If the number contains 2 or multiple of 2 at ones place it is
not a prime number.
Like 2782, 1322, 1238, 9876 etc.
Whatever is the number use this trick.
Let the number be 89
Divide this number by 8 and then 9, 8+9=17 and 7+1=8
First step = 89/8
not divisible
Second step = 89/9 not divisible
3rd step
= 89/17 not divisible
Final step =89/8
not divisible
So the number is Prime number.
Now check number 139
Important Note If number
contains one at any position doesn’t check the number for one.
First step =139/3
not divisible
Second Step = 139/9
not divisible
Third step = 139/13 not divisible
Final step = 139/4
not divisible.
So the number is Prime number.
Now check the number 453
First step = 453/4
not divisible
Second Step = 453/5 not divisible
Third step = 453/3
= 151.
Since it is divisible so the number is not a Prime number.
This tricks works for a large number also. It will not take
your much time to practice this trick.
Sunday, March 3, 2013
Trick to get square of two digit number?
How to square
the double digit number
This trick
use simple multiplication and addition to get square of two digit number with
in fraction of second. You can use this method to double any number from 11 to
99.Here we go
Let us start
with number 14
Square of
14= 14 ×14
14
×14
196
Right Hand
side digit = 4 * 4 = 16 ,So the first digit
is 6 and one carry
Second digit = 2(1×4)
+ 1 = 9
Third digit = 1 ×1
= 1
So the
answer is 196
General rule
for multiplication
2nd
digit 2(1*4) + 1 carry from first digit
1 4 4 * 4 = 16
3rd digit (1*1 + carry2nd digit) 1 4
1 9 6
now 23* 23
first digit 3*3 = 9
2nd digit = 2(2*3) + carry from first here it is 0 so 2nd digit = 12
3rd digit = 2 * 2 + carry from second digit here it is 1 = 5
answer is 529
Try 23 27 87
99 34 and share the result with others in comment
Saturday, March 2, 2013
Trick to remember the table of 19.
Trick to remember the table of 19.
Since it is
easy to remember the table of 20. So you can obtain the table of 19 from table
of 20.
To get table
of 19 just minus the number from 20’s table for e.g. if you want to get value of
19 × 5 just minus the 5 from 20 × 5
19×5 = (20 ×
5) -5 = 95.
20 × 1 = 20 19 ×1 = (20-1) = 19
20 × 2 = 40 19 × 2 = (40-2) = 38
20 × 3 = 60 19 × 3 = (60-3) = 57
20 × 4 = 80 19 × 4 = (80-4) = 76
20 × 5 = 100
19 × 5 = (100-5) = 95
20 × 6 = 120 19 ×6 = (120-6) = 114
20 × 7 = 140 19 ×7
= (140-7) = 133
20 × 8 = 120 19 ×8 =(160-8) = 152
20 × 9 = 180 19 ×9 = (180-9) = 171
20 × 10 = 200 19 ×10 = (200-10) = 200
This trick
can be further extended to 199,299,399 …… 1999.
Try it and
share with others.
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