Use Euler's method to approximate the solutions for each of the following initial-value problems.
a. y' = te3t − 2y, 0≤ t ≤ 1, y(0) = 0, with h = 0.5
b. y' = 1 + (t − y)2, 2≤ t ≤ 3, y(2) = 1, with h = 0.5
c. y' = 1 + y/t, 1≤ t ≤ 2, y(1) = 2, with h = 0.25
d. y' = cos 2t + sin 3t, 0≤ t ≤ 1, y(0) = 1, with h = 0.25