Estimate the value of the integral from negative 1 to 3 of x cubed, dx by using the Trapezoidal Rule with n = 4

Question

a)8

b)19

c)22

d)36

I think its c

Answer 1

Δx (3 - (-1))/4 = 1;T₄ = 1/2((-1)³ + 3³ + 2(0³ + 1³ + 2³)) = 22

∫_-1³x³dx = x⁴_-1³ = 81/4 - 1/4 = 20.