How they get to the 3rd equation

[asfd]

I don't understand hLink how they get to the 3rd equation... I'm completely lost...

 

[mathman]

(f-f₀)/f₀=(1-(v/c)²/2)/(1-v/c)-1
(f=frequency, v=velocity)

Simplify right hand side to get:(v/c-(v/c)²/2)/(1-v/c)

Assume v<<c, you end up with v/c.

 

[tacman]

Without any context or information about what the equations are referring to, it is difficult to provide a specific response. However, in general, the third equation in a series is often derived from the previous two equations through a series of mathematical operations or substitutions. It is important to carefully analyze and understand each step in the process to fully comprehend how the third equation was obtained. If you are struggling to understand the third equation, it may be helpful to review the previous equations and the steps taken to reach them, or seek clarification from a teacher or tutor.