Solving for the DTFT of (0.8)^n u[n]

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Homework Statement


Compute the DTFT of the following signal.

x[n] = (0.8)^n u[n]


Homework Equations


Properties of DTFT


The Attempt at a Solution


Well, my professor tells me to use the properties of DTFT to solve this. I'd love to - except I don't know what the DTFT of (0.8)^n is. I've tried looking it up on the DTFT table, but couldn't find any, can someone tell me what it is?
 
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It's in the DTFT pairs here:

http://www.neng.usu.edu/classes/ece/5630/notes_transforms.pdf on page 20.

but maybe the prof wants you to derive it from the properties you already have in your text?
 
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Thread 'Prove that the integral is equal to ##\pi^2/8##'

Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
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