A street light is mounted at the top of a 14 ft tall pole. A woman 6 ft tall walks away from the pole with a speed of 6 ft/sec along a straight path. How fast is the tip of her shadow moving when she is 45 ft from the base of the pole?
use similar triangles. create two similar triangles based on the information tehn take the derivative
i dont understand how to do that
check out this website and go to example 2, it has a similar question with different numbers =) http://www.math.wfu.edu/tutorials/Math111/RelatedRates.pdf
okay carra i will solve it, im done with my hw
For the answer try 9/2 (ft/sec) , let me know whether it is correct. If it is, I will post the solution.
no not the answer
k let me see if i did anythinig wrong, brb
can you double check the question?
question is correct
okay, let me check my work again
can you try 4/3 or 1.3
no i sorry
im on the case
do you mind, i will use twiddla
click on that
Okay so cantorset, this is what im doing: y/6 = (y+x)/14 => look at that in terms of similar triangles. Cross multiply and simplify: 14y = 6x + 6y 14(dy/dt)=6(dx/dt) + 6(dy/dt) 8 d(y/dt) = 6 (dx/dt) 8(dy/dt) = 6 * 6 8(dy/dt) = 36, solve for dy/dt = 9/2. What am I doing wrong?
its a whiteboard
carra try 10.5
uploading the screen
http://i53.tinypic.com/o6i8b7.jpg there's the screen
i gtg now, bbl
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