Cauchy-Riemann Equations test problem

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Multiple-choice question asking whether f(x+iy) = e^x (y + cos y + i sin y) is analytic using the Cauchy-Riemann equations, with four answer options A to D giving yes or no with partial derivative comparisons.


I cannot figure it out which choice is correct
Please help me
Please!
Thank you in advance
 
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What is the real part of $f(x+iy)$? That is $u(x,y)$.
What is its partial derivative with respect to $x$? That is $u_x$.
 
Klaas van Aarsen said:
What is the real part of $f(x+iy)$? That is $u(x,y)$.
What is its partial derivative with respect to $x$? That is $u_x$.
Is the correct answer is choice D ?
I already done it by using partial derivatives and compare them
 
jaychay said:
Is the correct answer is choice D ?
I already done it by using partial derivatives and compare them
It seems you are doing some online exam.
I'd rather not validate answers for something like that.
 
Klaas van Aarsen said:
It seems you are doing some online exam.
I'd rather not validate answers for something like that.
Sir, it's not an online exam
It's my assignment that I try to do on my own
I translate it from my math textbook in my country into English
I really want to become better at math.

If you still don't believe or you think I try to lie to you
Here is the original form of math textbook in my country

Thai-language text problem: Use the Cauchy-Riemann equations to test whether the function f(x+iy) = e^x (y + cos y + i sin y) is an analytic function in the complex number system, and why.
 
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Have you at least established what your u and v are?

As Klaas stated, $\displaystyle \begin{align*} u = \mathcal{Re}\left( f \right) = \mathrm{e}^x \left[ y + \cos{ \left( y \right) } \right] \end{align*}$ and $\displaystyle \begin{align*} v = \mathcal{Im}\left( f \right) = \mathrm{e}^x \sin{ \left( y \right) } \end{align*}$. Surely you can evaluate the necessary partial derivatives and make a judgement...
 
Prove It said:
Have you at least established what your u and v are?

As Klaas stated, $\displaystyle \begin{align*} u = \mathcal{Re}\left( f \right) = \mathrm{e}^x \left[ y + \cos{ \left( y \right) } \right] \end{align*}$ and $\displaystyle \begin{align*} v = \mathcal{Im}\left( f \right) = \mathrm{e}^x \sin{ \left( y \right) } \end{align*}$. Surely you can evaluate the necessary partial derivatives and make a judgement...
Thank you very much for guiding it for me.