This is Mathematical Modeling problem~

plz solve it

8: Determine the equilibrium positions of each of the following equations, and determine their stability. (#1) (12.17 .31 . mE=a(e 1) wrtha>0and> (b) d2 d _$= 55:: ' _:L' ' md2 a[e 1)+1s1n(dt) w1tha>0,>0end'y>0 (123 d3 1'! _ -433 + _+_ ' m 32 05(1 6) 7.205(t 2) w1tha>0,>0and7>0