General Friedmann equation - how to solve this differential equation?

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The discussion centers on solving the Friedmann equation, a key aspect of cosmology related to the scale factor of cosmic time. The participant expresses confusion despite prior coursework in differential equations. They receive advice to take the square root of the equation and separate variables, while also questioning which sign to use for the square root. The participant finds this guidance helpful and acknowledges their struggle with the material after a break. The conversation highlights the challenges of applying mathematical concepts in cosmological contexts.
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Homework Statement
Solve the differential equation
Relevant Equations
(adot / a)^2 = k / a^q
friedman.png


Hello fellow physicists, I am taking a course "Introduction to Cosmology" and I am asked to solve this equation called the Friedmann equation. I understand what it represents (scale factor of cosmic time) but I have no idea how to solve this differential equation, even though I took a whole course on solving those (Euler-Lagrange etc.)

Please give me a small pointer :)
 
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Take the square root (which sign is the right one?) and then separate variables.
 
vanhees71 said:
Take the square root (which sign is the right one?) and then separate variables.
Thanks! That was way more obvious than I thought. Summer break always breaks me up.
 
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