Gwhich of the following are second-order linear homogeneous recurrence relations with constant coefficients? circle all that apply and explain each answer. a. a_k=2a_(k-1)-5a_(k-2) b. b_k=kb_(k-1)+b_(k-2) c. c_k=c_(k-1)⋅c_(k-2)^2 d. d_k=3d_(k-1)-πd_(k-2) e. r_k=r_(k-1)-r_(k-2)-2 f. s_k=100s_(k-2) g. u_k=2u_(k-1)

An engine undergoes a cycle as shown in the diagram. during a complete cycle the work done by the gas is 28.5×103 j and the energy transferred thermally out is 99.4×103 j. there are 1.5×1024 gas molecules and they have three active degrees of freedom. 6. (6 pts) during which process(es) is energy transferred thermally into the gas? a. 1→2 b. 2→3 c. 4→1 d. 1→2 and 4→1 e. none of the above