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differentiation

how would you differentiate

y=sin(In x)

what rule would you use and why?
Original post by HelloImCool
how would you differentiate

y=sin(In x)

what rule would you use and why?


Chain because you have a function inside a function.

Bonus points if you spot what function is inside which.
Original post by RDKGames
Chain because you have a function inside a function.

Bonus points if you spot what function is inside which.


thank you .
ln x is inside sin ? idk lol

If you don't mind , could you tell me when to use the 3 rules because the responses i get from this forum are totally different from my teacher .


kind regards,
Original post by HelloImCool
thank you .
ln x is inside sin ? idk lol


Exactly.

If you don't mind , could you tell me when to use the 3 rules because the responses i get from this forum are totally different from my teacher .


The names are self-explanatory.


You use the product rule when you wish to differentiate an expression that is a PRODUCT of two functions in the form f(x)g(x)f(x)g(x), e.g. x2sin(x)x^2 \sin(x), or exlogxe^x \log x

You use the quotient rule when you wish to differentiate an expression that is a QUOTIENT of two functions in the form f(x)g(x)\dfrac{f(x)}{g(x)}, e.g. exsin(x)\dfrac{e^x}{\sin(x)}, or x3+1x5+x3+x+1\dfrac{x^3+1}{x^5+x^3+x+1}

You use the chain rule when you wish to differentiate an expression that is a COMPOSITION of two functions in the form f(g(x))f(g(x)), e.g. sin(x2)\sin(x^2), or ex3e^{x^3}


Is this not what your teacher said...?

P.S. The quotient rule can often be avoided by simply rewriting f(x)g(x)\dfrac{f(x)}{g(x)} as f(x)g(x)1f(x)g(x)^{-1} and then using the product rule + chain rule. I.e. x2ex=x2ex\dfrac{x^2}{e^x} = x^2e^{-x}
(edited 6 years ago)
Original post by RDKGames
Exactly.



The names are self-explanatory.


You use the product rule when you wish to differentiate an expression that is a PRODUCT of two functions in the form f(x)g(x)f(x)g(x), e.g. x2sin(x)x^2 \sin(x), or exlogxe^x \log x

You use the quotient rule when you wish to differentiate an expression that is a QUOTIENT of two functions in the form f(x)g(x)\dfrac{f(x)}{g(x)}, e.g. exsin(x)\dfrac{e^x}{\sin(x)}, or x3+1x5+x3+x+1\dfrac{x^3+1}{x^5+x^3+x+1}

You use the chain rule when you wish to differentiate an expression that is a COMPOSITION of two functions in the form f(g(x))f(g(x)), e.g. sin(x2)\sin(x^2), or ex3e^{x^3}


Is this not what your teacher said...?

P.S. The quotient rule can often be avoided by simply rewriting f(x)g(x)\dfrac{f(x)}{g(x)} as f(x)g(x)1f(x)g(x)^{-1} and then using the product rule + chain rule. I.e. x2ex=x2ex\dfrac{x^2}{e^x} = x^2e^{-x}


Thanks. Really appreciate your help.

My teacher only said use product rule for 2 functions of x and if you see a division is quotient rule

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