Use Euler's method to approximate the solutions for each of the following initial-value problems.
a. y' = (2 − 2ty)/(t2 + 1) , 0≤ t ≤ 1, y(0) = 1, with h = 0.1
b. y' = y2/(1 + t), 1≤ t ≤ 2, y(1) = −(ln 2)−1, with h = 0.1
c. y' = (y2 + y)/t, 1≤ t ≤ 3, y(1) = −2, with h = 0.2
d. y' = −ty + 4ty−1, 0≤ t ≤ 1, y(0) = 1, with h = 0.1