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anonymous
 one year ago
Find the derivative of f(x) = 8 divided by x at x = 1.
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@ganeshie8 @hero @dan815 @perl @pooja195 @solomonzelman @mathstudent55 @zepdrix @usukidoll @
anonymous
 one year ago
Find the derivative of f(x) = 8 divided by x at x = 1. 4 0 8 8 @ganeshie8 @hero @dan815 @perl @pooja195 @solomonzelman @mathstudent55 @zepdrix @usukidoll @

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zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3Remember your exponent rule? :)\[\Large\rm \frac{1}{x}=x^{1}\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0no i dont; i dont know anything

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3\[\Large\rm f(x)=\frac{8}{x}\]Applying this exponent rule,\[\Large\rm f(x)=8x^{1}\]

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3Then simply apply your power rule to take derivative! :) The 1 comes down to multiply, then subtract 1 from the exponent. ya?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0would it be 8? @zepdrix

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0wait never mind, why would i subtract?

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3\[\Large\rm f(x)=x^n\]Power rule tells us how to deal with polynomials,\[\Large\rm f'(x)=nx^{n1}\]

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3Example:\[\Large\rm g(x)=4x^{3}\qquad\to\qquad g'(x)=4\cdot3x^{31}\]\[\Large\rm g'(x)=12x^{2}\]

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3you don't know anything? +_+ lol that's not good

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0i dont please help? @zepdrix can u take me step by step with my example

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3Nooo I don't wanna give you the answer :D I think you can do it. Let's work on a problem that's very similar. Given that \(\large\rm f(x)=\frac{4}{x^{2}}\) find f'(x) at x=2. We'll first write f(x) differently using our exponent rule,\[\large\rm f(x)=4x^{2}\]Then we'll apply our power rule to take our derivative: The 2 comes down in front, and then we subtract 1 from the exponent:\[\large\rm f'(x)=4\cdot(2)x^{21}\]\[\large\rm f'(x)=8x^{3}\]Let's apply our exponent rule in reverse, putting the x back into the bottom,\[\large\rm f'(x)=\frac{8}{x^3}\]Evaluating this function at x=2 gives us:\[\large\rm f'(2)=\frac{8}{2^3}\]\[\large\rm f'(2)=1\]

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3yayyy :) there are some stepssss

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3When you apply your power rule, be careful when dealing with negative exponents! If we have a 1 exponent, subtracting 1 from that will not give us 0, it will give us 2

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0im not asking for the answer I'm just trying to go step by step with my example with you

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so next would be f(x)=8x

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3no, we have 8x^(1) :O it gains a power of 1 when it comes up

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3Then apply your power rule, the 1 comes down in front as a multiplier, and the power decreases to 2.\[\large\rm f'(x)=8(1)x^{2}\]Simplify before plugging in your value,\[\large\rm f'(x)=\frac{8}{x^2}\]

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3Then plug in your 1 :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so then its f(x)=8/1^2

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0what do i do next? @zepdrix

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3\[\large\rm f'(1)=\frac{8}{(1)^2}\]ya, then simplify.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0them it will be f(x)=8/1 right? @zepdrix

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so the answer would be 8? @zepdrix

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so is the answer 8?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0but would f(1)=8/1^2=8? @zepdrix

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.3when you square 1, you get 1.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0can you help me with another? @zepdrix

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Find the derivative of f(x) = 12x2 + 9x at x = 6. 112.5 135 90 108 @zepdrix
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