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hiramoby
 3 years ago
Given xy=9 find dy/dt when x = 7 and dx/dt=7
hiramoby
 3 years ago
Given xy=9 find dy/dt when x = 7 and dx/dt=7

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hiramoby
 3 years ago
Best ResponseYou've already chosen the best response.0the answers are in the screen shot

Australopithecus
 3 years ago
Best ResponseYou've already chosen the best response.1dy/dt xy = 9 dy/dt xy = 9 xy' = 9 y' = 9/7

Australopithecus
 3 years ago
Best ResponseYou've already chosen the best response.1dx/dt xy =  9 yx' =  9 y(7) =  9 y =9/7 y = 9/7

Australopithecus
 3 years ago
Best ResponseYou've already chosen the best response.1I think this is right just using implicit differentiation

Australopithecus
 3 years ago
Best ResponseYou've already chosen the best response.1and chain rule

Australopithecus
 3 years ago
Best ResponseYou've already chosen the best response.1do you understand how I got my answer?

hiramoby
 3 years ago
Best ResponseYou've already chosen the best response.0Thank you, help me with my other question please. Yes I did , i was stuck after implicit.. thought it could not be this easy

Australopithecus
 3 years ago
Best ResponseYou've already chosen the best response.1ok send me a link to your next question

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1@Australopithecus I'm confused by what you did in your steps. When you took the derivative, did you remember to apply the product rule? :o

hiramoby
 3 years ago
Best ResponseYou've already chosen the best response.0austra i sent you a mail

Australopithecus
 3 years ago
Best ResponseYou've already chosen the best response.1I dont need to apply the product rule because we are taking the derivative in respect to t not in respect to y or x so they are treated as constants

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1No both are variables, unless you're taking a partial derivative, you need to apply the product rule.

Algebraic!
 3 years ago
Best ResponseYou've already chosen the best response.2both are functions of time.

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1I did the steps using the product rule and I also came up with 9/7... so maybe just a little bit of luck XD lol

Australopithecus
 3 years ago
Best ResponseYou've already chosen the best response.1oh I guess so :)

Algebraic!
 3 years ago
Best ResponseYou've already chosen the best response.2d/dt( x*y=9) = dx/dt*y + x*dy/dt =0 dy/dt = dx/dt *y/x

Australopithecus
 3 years ago
Best ResponseYou've already chosen the best response.1can you break down the steps clearer algebraic!

Algebraic!
 3 years ago
Best ResponseYou've already chosen the best response.2it's just use of the product rule on x*y =9 then solving algebraically for dy/dt

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1dw:1351050464937:dw Leibniz notation (with the differentials) can be a little tricky to understand. Maybe if you see it with the primes it'll make some sense :o

Australopithecus
 3 years ago
Best ResponseYou've already chosen the best response.1yeah that makes a lot more sense seeing as I had to take the derivative on both sides of the equation and I kept getting 0 Thanks for the refresher

Algebraic!
 3 years ago
Best ResponseYou've already chosen the best response.2you do take the derivative on both sides and you do 'get 0'
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