Which of the following transformations are linear? a. t(f(t))=f′(t)+4f(t) t(f(t))=f′(t)+4f(t) from c[infinity] c[infinity] to c[infinity] c[infinity] b. t(x+iy)=9x−iy t(x+iy)=9x−iy from c c to c c c. t(x0,x1,x2,…)=(1,x0,x1,x2,…) t(x0,x1,x2,…)=(1,x0,x1,x2,…) from the space of infinite sequences into itself d. t(f(t))=f′(t)+6f(t)+8 t(f(t))=f′(t)+6f(t)+8 from c[infinity] c[infinity] to c[infinity] c[infinity] e. t(f(t))=f(7) t(f(t))=f(7) from p2 p2 to r r f. t(f(t))=f(−t) t(f(t))=f(−t) from p3 p3 to p3 p3