What is the Integral of exp(-kx^2)?

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SUMMARY

The integral of exp(-kx^2) over infinity is calculated using the substitution method. By letting u = x√k, the integral transforms to ∫_{-∞}^∞ e^{-u^2} du, which equals √π. Consequently, the final result for the integral ∫_{-∞}^∞ e^{-kx^2} dx is (1/√k) * √π, simplifying to √(π/k). This method is essential for evaluating Gaussian integrals in mathematical analysis.

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Hi there,
what's the integral over infinity of exp(-kx^2 )? the integral of exp(-x^2) is sqrt(pi)...
appreciate the help! I can't find the answer anywhere and can't work it out myself..
 
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To integrate \int_{-\infty}^\infty e^{-kx^2} dx, let u= x\sqrt{k} so that du= dx \sqrt{k} and dx= du/\sqrt{k}.

Your integral becomes
\int_{-\infty}^\infty e^{-kx^2}dx= \frac{1}{\sqrt{k}}\int_{-\infty}^\infty e^{-u^2}du
 

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