What is the arclength of (ln(t+3),lnt/t)(ln(t+3),lntt) on t in [1,2]t[1,2]?

1 Answer
Jul 9, 2018

approx 0.42877422740.4287742274

Explanation:

We have

x(t)=ln(t+3)x(t)=ln(t+3) then

x'(t)=1/(t+3)

y(t)=ln(t)/t

then

y'(t)=(1/t*t-ln(t))/t^2

y'(t)=(1-ln(t))/t^2
and we have to integrate
int_1^2sqrt((1/(t+3))^2+((1-ln(t))/t^2)^2)dt
by a numerical method we get

approx 0.4287742274