NCERT Class XI Mathematics - Binomial Theorem - Solutions
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Question : 23
Total: 36
In the expansion of ( 1 + a ) m + n
Solution:
Suppose a m ( 1 + a ) m + n
NowT r + 1
C r ( 1 ) m + n − r ( a ) r
C r a r
On comparing power of a ina m T r + 1
Thus the coefficient ofa m
C m
Suppose an occurs in the (r + 1)th term in the expansion of( 1 + a ) m + n
On comparing power of a ina n T r + 1
Thus the coefficient ofa n
C n
From (i) & (ii) we proved that coefficient of am & an in expansion( 1 + a ) m + n
Now
On comparing power of a in
Thus the coefficient of
Suppose an occurs in the (r + 1)th term in the expansion of
On comparing power of a in
Thus the coefficient of
From (i) & (ii) we proved that coefficient of am & an in expansion
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