Evaluate A'(x) at x=1 and 3 :
a. A(x) = ∫₀ˣ 2t dt
b. A(x) = ∫₋₃ˣ 2t dt
c. A(x) = ∫₀ˣ sin t dt
d. A(x) = ∫₁ˣ |t-2| dt