Binomial Expansion

 

 

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Binomial Expansions

 

Factorials

 

Combination Symbol

 

Binomial Theorem

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Binomial Series

 

Algebra Main Page

 Binomial Theorem
for positive integral index
 
 
More Properties of the Binomial Theorem
 
General (r + 1) th term in ascending powers of b,
                        nCr an-rbn
 
Finding the middle term of the expansion (a + b)n,
     if n is even, there will be an odd numbers of terms.
        the middle term is the 0.5 (n + 2) th term.
     if n is odd, there will be an even number of terms.
        the middle terms are the 0.5 (n + 1) and 0.5 (n + 3) terms.
 
Finding coefficients and term independent of x.
 
    In the expansion of
                ,
                  (i) find the coefficient of x5
                 (ii) find the term independent of x.
 
   Find the general term of the expansion:
               
    coefficient of x5, equate the power of x to 5.
                        30 - 5r = 5
                                r = 5
 
   substitute value of r back into the general term. ignore the part in x, only the coefficient of x5 is needed.
                          10C5 (0.5)5 = -7 7/8
 
   term independent of x, equate the power of x to 0.
                        30 - 5r = 0
                                r = 6
 
   substitute r = 6 back into general term.
                          10C6 (0.5)6 = 3 9/32
 
 
The next page will deal with more examples.