Use the arc length formula to find the length of the curve

Question

Use the arc length formula to find the length of the curve

y = 7 − 4x,  −2 ≤ x ≤ 4

Answer 1

y' = - 4. So, length of arc is s = ∫_-2⁴(1 + (-4)²)^1/2dx = ∫_-2⁴√17dx = √17x_-2⁴ = √17(4 + 2) = 6√17 = 24.74