# Stuck with Integeration by substitutionWatch

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#1
Hi guyz.

I am stuck with following question of Integeration by substitution (P3). I was wondering if anyone can help me out.

Q1. Evaluaute by using substitution

∫ x*e^(-0.5x2)
-∞

Q. Use a substitution, followed by a change of letter in the integrand, to show that if σ>0,

-∞ e^(-xÂ²/2σÂ²)dx=σ∫-∞ e^[-1/(2xÂ²)]dx

Thanx
0
13 years ago
#2
Q1. Evaluaute by using substitution

∫ x*e^(-0.5x2)
-∞

Q. Use a substitution, followed by a change of letter in the integrand, to show that if σ>0,
∫∞-∞ e^(-xÂ²/2σÂ²)dx=σ∫∞-∞ e^[-1/(2xÂ²)]dx
You could try working backwards, writing the term on the right as
Unparseable or potentially dangerous latex formula. Error 4: no dvi output from LaTeX. It is likely that your formula contains syntax errors or worse.
\int_{-\infty}^{\infty} e^{lna-\frac{1}{2v^{2}} dx
0
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