i)Find h'(2) given that h(x)=f(g(x)), f(u)=u^2-1, g(2)=3, g'(2)=-1 ii) let y=f(x^2+3x-5). find dy/dx when x=1, given that f'(-1)=2
Last edited by mr fantastic; Aug 12th 2009 at 04:02 PM. Reason: Changed post title
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Just use the chain rule: You can now just substitute to get
Let When , so we have
Originally Posted by adkinsjr Let When , so we have where did the 5 come from in the last line
Originally Posted by skeske1234 where did the 5 come from in the last line The 5 is the derivative at
Originally Posted by adkinsjr Just use the chain rule: You can now just substitute to get not sure what you mean.... i sorry don't follow that.
Originally Posted by skeske1234 not sure what you mean.... i sorry don't follow that. We have the function if we set we get the function (notice how I substituted ). We use the chain rule to differentiate: . . Do you understand how I got ? If so, then we have
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