1. The problem statement, all variables and given/known data light signal of frequency 33 MHz is reflected off a (radio)mirror that is moving toward you at half the speed of light. What is the reflected frequency in Hz? 2. Relevant equations f_f = f*sqrt((1-v/c)/(1+v/c) 3. The attempt at a solution The mirror and light wave are approaching you, so you use the receding/red shift equation (shown above). but when you plug in .5c for v and f - 33MHz you get 19.1MHz as the answer which is wrong. According to the solution, we need to get rid of the square root because "Doppler Shift from Mirror is the same". What does that mean???