Differentiate e^(a^2 z) with respect to z

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Homework Help Overview

The discussion revolves around differentiating various exponential functions with respect to the variable z, where a is treated as a constant independent of z. The functions include both real and complex exponentials.

Discussion Character

  • Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants explore differentiation techniques for different forms of exponential functions, questioning the treatment of constants and the application of the chain rule. There is a focus on ensuring correct differentiation of complex exponentials.

Discussion Status

There is ongoing verification of differentiation results, with participants providing corrections and alternative approaches. Some guidance has been offered regarding the simplification of complex exponentials during differentiation.

Contextual Notes

Participants are discussing the implications of treating 'a' as a constant and the necessity of applying the chain rule in certain cases. There is an emphasis on differentiating without converting to trigonometric forms.

UrbanXrisis
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I am to differentiate with respect to z, where a is independent of z... (am assuming that that a is a constant?)

a. [tex]e^{a^2 z}[/tex]=diff=>[tex]a^2 e^{a^2 z}[/tex]

b.[tex]e^{ia z}=cos(az)+isin(az)[/tex]=diff=>[tex]-sin(az)+icos(az)[/tex]

c. [tex](e^{-i z})^2=cos(2z)-isin(2z)[/tex]=diff=>[tex]-sin(2z)-icos(2z)[/tex]

d. [tex]e^{-iz^2}[/tex]=diff=>[tex]-sin(z^2)-icos(z^2)[/tex]

e. [tex]e^{az}+e^{-az}[/tex]=diff=>[tex]ae^{az}+-ae^{-az}[/tex]

do these look alright?
 
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UrbanXrisis said:
(am assuming that that a is a constant?

Whatever it is, it does not depend on z, so when z changes, a does not change. That's the definition of "constant".

Double check b,c,d; you're forgetting the derivative of the interior (chain rule).

note: you don't need to write e^ix in temrs of cis(x) b4 taking the derivativ; complex exponentials differentiate like regular ones, i.e.

(e^iax)' = ia(e^iax)
 
Last edited:
for b.
[tex]-azsin(az)+azicos(az)[/tex]

for c.
[tex]2isin(2z)-2cos(2z)[/tex]

for d.
[tex]-4z(icos(z^2)+sin(z^2))+2(cos(z^2)-isin(z^2))[/tex]

how does it look?
 
let me correct myself:
for b:
[tex]-asin(az)+aicos(az)[/tex]

for c:
[tex]-2sin(2z)-i2cos(2z)[/tex]

for d:
[tex]-2z(sin(z^2)+icos(z^2))[/tex]
 
UrbanXrisis said:
let me correct myself:
for b:
[tex]-asin(az)+aicos(az)[/tex]

for c:
[tex]-2sin(2z)-i2cos(2z)[/tex]

for d:
[tex]-2z(sin(z^2)+icos(z^2))[/tex]
Looks good. But as quasar987 said before, just try to differentiate it without changing to cis function.
[tex](e ^ {iaz})' = ia e ^ {iaz}[/tex], which is a lot easier, right? This answer is exactly the same as yours:
[tex]ia e ^ {iaz} = ia (\cos (az) + i \sin (az)) = ia \cos (az) - a \sin (az)[/tex]
 

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