Evaluate Integral as a power series Question

grib90

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Dec 4, 2007
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Evaluate the integral as a power series and find the radius of convergence:

f(x) = [e^(-t^3)]dt

Not many useful examples of these I can find, so any help is appreciated.
 
ex=k=0xkk!et3=k=0(t3)kk!=k=0(1)kt3kk!\displaystyle e^x = \sum\limits_{k = 0}^\infty {\frac{{x^k }}{{k!}}} \quad \Rightarrow \quad e^{ - t^3 } = \sum\limits_{k = 0}^\infty {\frac{{\left( { - t^3 } \right)^k }}{{k!}}} = \sum\limits_{k = 0}^\infty {\frac{{\left( { - 1} \right)^k t^{3k} }}{{k!}}}
 
pka said:
ex=k=0xkk!et3=k=0(t3)kk!=k=0(1)kt3kk!\displaystyle e^x = \sum\limits_{k = 0}^\infty {\frac{{x^k }}{{k!}}} \quad \Rightarrow \quad e^{ - t^3 } = \sum\limits_{k = 0}^\infty {\frac{{\left( { - t^3 } \right)^k }}{{k!}}} = \sum\limits_{k = 0}^\infty {\frac{{\left( { - 1} \right)^k t^{3k} }}{{k!}}}

Thanks for the reply. Since it's an integral wouldn't you have to integrate it? But how do you deal with factorials when integrating?
 
grib90 said:
Thanks for the reply. Since it's an integral wouldn't you have to integrate it? But how do you deal with factorials when integrating?

k is constant - term by term - thus does not affect integration
 
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