Question

Walking and rowing. Optimization. pls help me T^T

Answer 1

i got part a, how do i go abt part b?

Answer 2

\[t=\frac{ d }{v}=\frac{ 1 }{ 2 }(16+x^2)^\frac{ 1 }{ 2 }+\frac{ 1 }{ 3 }(6-x)\]
\[dt/dx = \frac{ 1 }{2 }x(16+x^2)^\frac{- 1 }{ 2 }-\frac{ 1 }{ 3}\]
dt/dx=0
\[x=\frac{ 8 }{ \sqrt{5} }\]

Answer 3

im cracking my head on how to do part b

Answer 4

so now u know x. compute the time (t_0) it actually takes her to get to the restaurant when rowing AND walking.

use pythagoras to compute the distance to the restaurant. so u have t_0>=d/v.

your unknow now is v

Answer 5

thanks! (:

Answer 6

u r welcome