Problem

6) Compute $\int_{C} x y d s$ where $C$ is line segment from $(2,4)$ to $(1,6)$.

Answer

Expert–verified
Hide Steps
Answer

Compute the integral to get the final answer \(\boxed{\frac{22\sqrt{5}}{3}}\).

Steps

Step 1 :Parameterize the line segment from (2,4) to (1,6) by setting \(x(t) = 2 - t\) and \(y(t) = 4 + 2t\) for \(0 \leq t \leq 1\).

Step 2 :Compute the differential \(ds = \sqrt{dx^2 + dy^2} = \sqrt{(-dt)^2 + (2dt)^2} = \sqrt{5} dt\).

Step 3 :Substitute the parameterization and differential into the integral to get \(\int_{0}^{1} x(t) y(t) ds = \int_{0}^{1} (2 - t)(4 + 2t) \sqrt{5} dt\).

Step 4 :Compute the integral to get the final answer \(\boxed{\frac{22\sqrt{5}}{3}}\).

link_gpt