Magnification factor is the ratio of ______

What is meant by phase difference or phase angle in forced vibrations?

The equation m(d²x/ dt²) + c (dx/dt) + Kx = F₀ sin ωt is a second order differential equation. The solution of this linear equation is given as

Which of the following statements is/are true?
1. Magnification factor is minimum at resonance
2.The maximum value of amplification factor increases as damping factor decreases
3.The maximum value of amplification factor increases as damping factor increases
4.Magnification factor is maximum at resonance