Gamma Function

Without LaTeX annotation:

Γ (t) = \int_{0}^{+ ∞} x^{t - 1} e^{- x} d x = \frac{1}{t} \prod_{n = 1}^{∞} \frac{{(1 + \frac{1}{n})}^{t}}{1 + \frac{t}{n}} \sim \sqrt{\frac{2 π}{t}} {(\frac{t}{e})}^{t}

With LaTeX annotation:

{\Gamma(t)} = {\int_{0}^{+\infty} x^{t-1} e^{-x} dx} = {\frac{1}{t} \prod_{n=1}^\infty \frac{\left(1+\frac{1}{n}\right)^t}{1+\frac{t}{n}} } \sim {\sqrt{\frac{2\pi}{t}} \left(\frac{t}{e}\right)^t}

XeLaTeX rendering:

$\mathit \Gamma(t)} = {\int_{0}^{+\infty} x^{t-1} e^{-x} dx} = {\frac{1}{t} \prod_{n=1}^\infty \frac{\left(1+\frac{1}{n}\right)^t}{1+\frac{t}{n}} } \sim {\sqrt{\frac{2\pi}{t}} \left(\frac{t}{e}\right)^t$