# Help a mature student! Friedmann equation!

by stormymouse
Tags: equation, friedmann, mature, student
 Mentor P: 8,316 Ok, so either you're not coming back, or you still can't attempt the problem. I'll give you a few hints: You vasically have two parametric functions a(y)=L(1-cos(y)) and t(y)=M(y-sin(y)), for some constants L and M. In the Friedmann equation, we have a term $a'=\frac{da}{dt}$. Using the chain rule we can write $$\frac{da}{dt}=\frac{da/dy}{dt/dy}$$ from which you should be able to solve.