(d) Are the follawing functions ore-to-one, onto or bjjection? (i) f(x)=2x+1 (ii) f(x)=x2+7 (iii) f(x)=(x+1)/(x+2) (iv) f(x)=x3 (v) f(x)=x1+ex 2. Let n is a constant positive integer. Define a relation RZZ by (x,y)R(nxykz,xy=kn). Prove that R is an equivalence relation on z 3. Rrove that S3 is a group. 4. Find the solution of the requrrence relation an=7an116an2+12an3+n4n with a0=2,a1=0, and a2=5. Show your work step-by-step