dont have enough brain to solve a calc problem

[thestranger]

Joe is on the bank of a river that is 50 m wide and he wants to reach a point, P, located 400 m downstream on the other side. Joe can swim 5/4 m/s and run 13/2 m/s, and he will swim diagonally across the river to a point Q and then run along the (straight) river bank to P. In this question, we shall take steps to find out how Joe can reach the point P as quickly as possible.

(a) Suppose that Q is located x m downstream, and let us denote the point directly across the river from where Joe is by R. For what distance will Joe swim? run? Express your answers in terms of x.

Answers: Joe will swim xxxx m, and will walk xxxx m, where 0≤x≤400. Note. Your answers should be functions of x.

(b) For how long will Joe swim? run? Express your answers in terms of x.

Answer: Joe will swim for xxx s, and will walk for xxxx s, where 0≤x≤400. Note. Your answers should be functions of x.

(c) Find the total amount of time required for Joe to reach point P.

Answer: The time it takes for Joe to reach P is T(x)=xxx , where where 0≤x≤400. Note. Your answer should be a function of x.

(d) Find the value of x for which the T(x) attains its smallest possible value, and find this value.

Answer: The value of T(x) is smallest possible when x= xxxx m, and the least amount of time required for Joe to reach point P is xxxx s.

Solution: total time = time swimming + time running....time = distance / rate

TT (x) = [ 5 / 4 ] √ (50² + x²) + [ 13/ 2] [ 400 - x ]. dont know what to do next

 

[stapel]

Joe is on the bank of a river that is 50 m wide and he wants to reach a point, P, located 400 m downstream on the other side. Joe can swim 5/4 m/s and run 13/2 m/s, and he will swim diagonally across the river to a point Q and then run along the (straight) river bank to P. In this question, we shall take steps to find out how Joe can reach the point P as quickly as possible.

(a) Suppose that Q is located x m downstream, and let us denote the point directly across the river from where Joe is by R. For what distance will Joe swim? run? Express your answers in terms of x.

(b) For how long will Joe swim? run? Express your answers in terms of x.

(c) Find the total amount of time required for Joe to reach point P.

(d) Find the value of x for which the T(x) attains its smallest possible value, and find this value.

Solution: total time = time swimming + time running....time = distance / rate

TT (x) = [ 5 / 4 ] √ (50² + x²) + [ 13/ 2] [ 400 - x ]. dont know what to do next

I think that the last line is related to some portion of the exercise, but I can't be sure. Please reply with clarification, such as the part(s) of the exercise on which you've made attempts, along with all of your work and reasoning. Thank you!