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#### wolfsprint

##### New member

- Dec 31, 2012

- 17

i have no idea how to solve this problem and would really like how to?

- Thread starter wolfsprint
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- Thread starter
- #1

- Dec 31, 2012

- 17

i have no idea how to solve this problem and would really like how to?

You have a related rates problem. Have you drawn the triangle the problem forms? Have you labeled the triangle with what you know?

i have no idea how to solve this problem and would really like how to?

If not, that is step one. Then what are the equations related to a triangle we could use?

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- #3

- Dec 31, 2012

- 17

I understand i have to draw the x-axis and the y-axis and plot and join the dots to form a triangle but the problem is im having trouble understanding the positions of the ships

The 30 degrees north of east part?I understand i have to draw the x-axis and the y-axis and plot and join the dots to form a triangle but the problem is im having trouble understanding the positions of the ships

If we let the east-west axis be our x-axis, then 30 degrees north of east is $\frac{\pi}{6}$.

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- #5

- Dec 31, 2012

- 17

so A is the origin and when the ship sails north i put a dot a bit further up and for the 30 north of east i draw an imaginary x axis on the dot on the north direction and put a point in the 30 degrees direction? whats next?

That is what I would do, let A be the origin. Then the ship sailed 2 hours at 18km/h so the from A to B we have 36km.so A is the origin and when the ship sails north i put a dot a bit further up and for the 30 north of east i draw an imaginary x axis on the dot on the north direction and put a point in the 30 degrees direction? whats next?

Then the ship sailed at 30 degrees from point b for 2 hours to point C. What you want to find is the rate of change of the AC

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- #7

- Dec 31, 2012

- 17

ok so this is how i solved the problem :

After t hours i presumed the following

AB = 36+2t

BC = 36+2t

we need to find AC so

AC^2 = (36+2t)^2 + (36+2t)^2

AC = 12(Root)26

is this correct?

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- #8

- Dec 31, 2012

- 17

Thanks for understanding , and i would like to know if my method of solving is correct please?

Look at the this example page 192Thanks for understanding , and i would like to know if my method of solving is correct please?