- find the coefficient of x
^{40}in the expansion of (1/x^{2}+ x^{4})^{18} - find 1
^{st}4 terms in the expansion of ( 1 –x )^{-1/4} - show that there is no constant in the exoansion of (2x – x
^{2}/4)^{9} - using binomial theorem find the value of (9.9)
^{3}

find the coefficient of x^{40} in the expansion of (1/x^{2} + x^{4})^{18}

^{SOLUTION:}

Let (*r* + 1)^{th} term contains *x*^{40} in the binomial expansion of

Now,

For the coefficient of *x*^{40} ,

-36+6r=40

⇒6r* *= 40+36=76

⇒ *r *= 38/3,

which is impossible.

Thus, there is no term involving *x*^{40 }in ^{ }.

Find the value of (9.9)^{3}

^{SOLUTION:}

Show that there is no constant in the expansion of ^{}

^{ }

^{SOLUTION:}

By using general term of the binomial theorem,

Now, the exponent of x = 0

Thus, there is no constant in the given expansion as the r has negative value

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