Answer
Sum of terms = -4.0 + 4.0 + 8.0 + 12.0 = 20.0
Step-by-step explanation
Σ f(xᵢ) Δx
f(x) = 4x - 8
Δx = 0.5
x₁ = 0
x₂ = 4
x₃ = 6
x₄ = 8
when i = 1
x₁ = 0
f(x₁) = 4x₁ - 8
f(x₁) = 4(0) - 8
f(x₁) = 0 - 8
a₁ = f(x₁) = -8
when i = 2
x₂ = 4
f(x₂) = 4x₂ - 8
f(x₂) = 4(4) - 8
f(x₂) = 16 - 8
a₂ = f(x₂) = 8
when i = 3
x₃ = 6
f(x₃) = 4x₃ - 8
f(x₃) = 4(6) - 8
f(x₃) = 24 - 8
a₃ = f(x₃) = 16
when i = 4
x₄ = 8
f(x₄) = 4x₄ - 8
f(x₄) = 4(8) - 8
f(x₄) = 32 - 8
a₄ = f(x₄) = 24
Σ f(xᵢ) Δx
= Δx Σ f(xᵢ)
= 0.50 [-8 + 8 + 16 + 24)
= -4.0 + 4.0 + 8.0 + 12.0
= 20.0
Hope this Helps!!!