Friday, July 3, 2015

Algebraic Expressions and Equations and Identities




Algebra :
 Introduces the concept of variables, which allows an unknown quantity to be represented by a alphabets to manipulation in applications.

Algebraic expression: an expression which has variable ( alphabets), constant , operations  ( addition ,subtraction,multiplication division )and exponents. We try to understand relation between two different values of a statement .

For example
 3 times of  x means  ( statement )  3x( expression)
45 increased by some 6x ……… 45+6 x
30 decreased by some 2x ………30-2x


Types Algebraic expressions:
Monomial , binomial , trinomial  and multinomial expressions
Monomial Expression: An Algebraic expression with single term .
Example: 2x+3x …..x is only variable(addition with monomial with monomial)
         
                4xy - 3xy.....x and y are variables(subtraction with  monomial with monomial )

                 (3xy)(2x+5x) ......x and y are variables ( multiplication with monomial with binomial)


Binomial Expression: An algebraic expression with two terms ,
Examples : (5x+6y) +4x      ……x and y are variables(addition binomial with monomial )

                   (3a - 2b ) - (2a-2b)……a and b are variables. (subtraction with  binomial with binomial)
                   b3/2 * c/3……..b  and c are variables.

Trinomial Expression : An algebraic expression with three terms,
Examples: (3x+2y-7xy) +(2x+3y+5xy)…..X and Y are variables(addition)
                 ( 2a+ 5a + 7) - (a+3a+4) …… a is the only variable(subtractions)
                  (xy)(x+y+z) ………..x ,y and z are variables (multiplication)
Multinomials: An algebraic expression with one ,two or  more than  terms.
Examples:
                  m + 5mn – 7mn + nm

                  3 + 5x- 4xy + 5xy
  Polynomials:



An algebraic expression, in which variable(s) does (do) not occur in the denominator,
exponents of variable(s) are whole numbers and numerical coefficients of various
terms are real numbers, is called a polynomial.

Types of Polynomials on the basis of  degree:

Linear Polynomial:  A polynomial of degree 1 is called a linear polynomial.Linear equations contains variable  and  constant , variables (x , y etc  )does not have Exponents, square roots,and cube roots.



Example :2(x - 1) + 3(7x) - 10

Quadratic Polynomial:  A polynomial of degree 2 is called a quadratic polynomial.



              Quadratic Equation:  aX2 + bx + c = 0


Example: ax2 + bx + c

Cubic Polynomial:  A polynomial of degree 3 is called a cubic polynomial.



Bi-quadratic Polynomial:  A polynomial of degree 4 is called a biquadratic   polynomial


Algebraic equations  : An algebraic  expression is separated by equal to( = ), that means left hand side and right hand side. Algebra equation contains the terms like numbers, integers, fractions, roots, exponents etc. Linear equations and quadratic equations are the example of the algebraic equations.