Consider the picture(attached) if the point Q is on the shoreline rather than 1 mile inland.

a) Write the Travel time T as a function of a.

b)Use the result of part (a) to find the minimum time to reach Q.

c)The man can row at v1 miles per hour and walk at v2 miles per hour. Write the time T as a function of a. show that the critical number of T depends only on v1 and v2 and not on the distances.

d)Describe how to apply the result (c) to minimizing the cost constructing a power transmission cable tat costs c1 dollars per mile under water and c2 dollars per mile over land.