Mathematics
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OpenStudy (anonymous):
HELP ----> [Binomial Theorem]
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OpenStudy (anonymous):
Find the positive value of "a" so that the co-efficient of x^5 is equal to that of x^15 in the expansion
\[\huge (x^{2} + \frac{ a }{ x^{3} })^{10}\]
OpenStudy (anonymous):
the coefficient for x^5 i am getting is
\[\huge C _{5}^{10}a^{5}\]
OpenStudy (anonymous):
expanding it is useless actually
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OpenStudy (anonymous):
:D ikr but since woli can do it i dont mind :P
OpenStudy (cwrw238):
Hint: the seciond term is 10 (x*2)^9 * a/x^3
OpenStudy (anonymous):
the coeffiecient i am getting for x^15 is
\[\huge C _{1}^{10}a^1\]
OpenStudy (cwrw238):
right
OpenStudy (anonymous):
i equal them right
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OpenStudy (cwrw238):
yes
OpenStudy (anonymous):
252a^5 = 10 a --- > right ?
OpenStudy (anonymous):
\[\huge a^4 = \frac{ 10 }{ 252 }\]
\[\huge a= \sqrt[4]{\frac{ 10 }{ ? }}\]
OpenStudy (anonymous):
\[\huge \huge a= \sqrt[4]{\frac{ 10 }{ 252 }}\]
OpenStudy (cwrw238):
the ? is 252
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OpenStudy (cwrw238):
sorry i have to go right now
OpenStudy (anonymous):
answer is given different though
OpenStudy (anonymous):
@ganeshie8 help
OpenStudy (anonymous):
120 x^3= 10 a
120 x^3- 10 a=0
10a(12a^2-1)=0
a=0
or
a=1/12
:-|