1. The problem statement, all variables and given/known data This problem has to do with Doppler shifts as frequency changes with time. F(t)=fo(1-(v^2*T)/(c*sqrt(v^2*T^2+b^2)) T=t-To I want to find F'(t) . 2. Relevant equations See #1. 3. The attempt at a solution I expand F(t) to be F(t)=f0-(fo*v/c)*(1+(b/(vT))^2)^1/2 and again... F(t)=f0-(fo*v/c)*(1+b^2*v^-2*T^-2)^1/2 After this, I forgot all of my calculus I've learned couple years ago. :( Please help me remember what to do. I know you do exponent on the outside and then work inside... dot dot dot. Thanks.