CLASS_11_MATHS_SOLUTIONS_NCERT

Class XI Chapter 8 – Binomial Theorem Maths
______________________________________________________________________________
T C a b
r1
n nr r
r
Assuming that
.
2
x
occurs in the
m
T C x C x
m
1
1 m r r
r
r r r
Comparing the indices of x in
Therefore, the coefficient of
2
x
It is given that the coefficient of
m C 2
6
m!
6
2! m 2 !
m m
m
2m
2 !
m m1 12
2
m m
1 2 !
6
12 0
2
m m m
4 3 12 0
m m 4 3 m 4 0
m 4 m 3 0
m 4 0 or m 3 0
m
4
or m 3
r 1 th
2
x and in
is
m C2
term of the expansion of
Tr
1
, we obtain
1 x
r 2
2
x in the expansion
Thus, the positive value of m, for which the coefficient of
4.
m
2
x
is 6.
1 x
m
, we obtain
in the expansion
1 x
m
is 6, is
Printed from Vedantu.com. Register now to book a Free LIVE Online trial session with a
Top tutor.