Can someone please explain it to me ASAP??!!! This is Length of Curves. The arc length of the curve is approximately is 3.493 was wrong answer. What is supposed to be?

Write and simplify the integral that gives the arc length of the following curve on the given interval. necessary, use technology to evaluate or approximate the integral. y= - cos (3x), for OSXs Set up the integral that gives the arc length of the curve. Select the correct choice below and fill in the answer box to complete your choi ype an exact answer.) A. L = () dy - 1 VB L = 1 1 +9 sin 23x dx b. The arc length of the curve is approximately 3.493 (Round to three decimal places as needed.)