Solve Derivative of y=e^cosx*sinx

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SUMMARY

The derivative of the function y = e^(cos(x)) * sin(x) is calculated using the product and chain rules of differentiation. The correct derivative is y' = e^(cos(x)) * (cos(x) - sin^2(x)). The discussion emphasizes that e should not be treated as e^x but rather as e raised to the power of a function, specifically e^(cos(x)). The application of the chain rule and product rule is essential in deriving the solution accurately.

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Homework Statement


Find the derivativce of y=e^cosx*sinx

Homework Equations





3. The Attempt at a Solution

i`m just unsure of whether e should be treated as e^x because its not that.. or if e should be treated like an f(x)a^x to f`(x)a^xlna, or if it is still considerd e^x.. here is my attempt.

y`=e^cosx*(-sinx)*(sinx) + (cosx)(e^cosx)

y`= e^cosx(cosx - sin^2x)
 
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Plutonium88 said:

Homework Statement


Find the derivative of y=e^cosx*sinx

Homework Equations



3. The Attempt at a Solution

i`m just unsure of whether e should be treated as e^x because its not that.. or if e should be treated like an f(x)a^x to f`(x)a^xlna, or if it is still considered e^x.. here is my attempt.

y`=e^cosx*(-sinx)*(sinx) + (cosx)(e^cosx)

y`= e^cosx(cosx - sin^2x)

If you're differentiating y = (sin(x))ecos(x), then what you have done is fine.

Writing ax as ex ln(a) can be helpful at times, but writing e in terms of some other constant generally isn't helpful when differentiating.
 
SammyS said:
If you're differentiating y = (sin(x))ecos(x), then what you have done is fine.

Writing ax as ex ln(a) can be helpful at times, but writing e in terms of some other constant generally isn't helpful when differentiating.
Ah i just realized something... e^x = e^cosx in the sense that cosx is `x`. right?

And also thank you for your help.
 
Plutonium88 said:

Homework Equations

The chain rule. ##(f\circ g)'(x)=f'(g(x))g'(x)##
The product rule. ##(fg)'(x)=f'(x)g(x)+f(x)g'(x)##


Plutonium88 said:
i`m just unsure of whether e should be treated as e^x because its not that..
Keep in mind that ##e^{f(x)}=exp(f(x))=(\exp\circ f)(x)##. So you will need the chain rule. You will also need the product rule to find f'(x).
 
Fredrik said:
The chain rule. ##(f\circ g)'(x)=f'(g(x))g'(x)##
The product rule. ##(fg)'(x)=f'(x)g(x)+f(x)g'(x)##



Keep in mind that ##e^{f(x)}=exp(f(x))=(\exp\circ f)(x)##. So you will need the chain rule. You will also need the product rule to find f'(x).

all right, thanks man.
 

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