Saturday

February 28, 2015

February 28, 2015

Posted by **Darcy ( Please Reply, thank you)** on Monday, December 9, 2013 at 6:05am.

- Differential Calculus -
**Reiny**, Monday, December 9, 2013 at 8:50amplace ship B 65 miles east of ship A and mark them that way.

Let the time passed be t hrs

Draw a line BP , so that P is between A and B showing the distance traveled in those t hours.

Draw a line downwards AQ showing the distance traveled by ship A.

Join PQ to get the right-angled triangle APQ

AP = 65-10t

AQ = 15t

let D be the distance between P andQ

D^2 = (65-10t(^2 = (15t)^2

2D dD/dt = 2(65-10t)(-10) = 2(15t)(15)

for a minimum of D , dD/dt = 0

so 2(10)(65-10t) = 2(15t)(15)

divide by 10

2(65-10t) = 3(15t)

130 - 20t = 45t

65t = 130

t = 130/65 or 2 hrs

They will be closest at 9:00 + 2:00 or 11:00 am

and that distance is ....

D^2 = (65-20)^2 + 30^2

= 2925

D = √2925 = appr 54.1 miles

check my arithmetic

**Answer this Question**

**Related Questions**

CALCULUS!!!!! - At 9am, ship B was 65 miles due east of another ship, A. Ship B ...

calculus - At 9am, ship B was 65 miles due east of another ship, A. Ship B was ...

calculus - Optimization At 1:00 PM ship A is 30 miles due south of ship B and is...

calculus - At 1:00 p.m. ship A is 25 km due north of ship B. If ship A is ...

calculus - At noon, ship A is 100 kilometers due east of ship B. Ship A is ...

Calculus - "At 9am ship A is 50 km east of ship B. Ship A is sailing north at ...

Calculus - At 1:00 p.m. ship A is 25 km due north of ship B. If ship A is ...

Calculus - At noon, ship A is 10 nautical miles due west of ship B. Ship A is ...

Calculus - At noon, ship A is 10 nautical miles due west of ship B. Ship A is ...

Calculus - At noon, ship A is 10 nautical miles due west of ship B. Ship A is ...