Question

need help with a related rates problem. ship A is 100km west of ship B at 12:00. Ship A then sails south at 35km/h and ship B sails north at 25km/h. How fast is the distance between the ships changing at 4:00 PM?

Answer 1

(100)^2 +(35t+45t)^2

Answer 2

enjoy. i think equation is something like
\[(A+B)^2 + 100^2=D^2\] and then
\[2(A+B)(A'+B')=2DD'\]
or
\[(A+B)(A'+B')=DD'\] plug in numbers solve for D'

Answer 3

\[A=4\times 35=140\]
\[B=4\times 25=100\]
\[A'=35\]
\[B'=25\]
\[D=\sqrt{240^2+100^2}\] and that is that