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​For a positive integer p, consider the holomorphic function:f(z)=sin⁡zzp,for z∈C∖{0}.For which&nbsp
Question

For a positive integer p, consider the holomorphic function:f(z)=sinzzp,for zC{0}.For which values of p does there exist a holomorphic function g:C{0}Csuch that f(z)=g(z), for zC{0}?\text{For a positive integer } p, \text{ consider the holomorphic function:} \\f(z) = \frac{\sin z}{z^p}, \quad \text{for } z \in \mathbb{C} \setminus \{0\}.\text{For which values of } p \text{ does there exist}\\\text{ a holomorphic function } g: \mathbb{C} \setminus \{0\} \to \mathbb{C} \\\text{such that } f(z) = g'(z), \text{ for } z \in \mathbb{C} \setminus \{0\}?​​

A.

All even integers .

B.

All odd integers.

C.

All multiples of 3 .

D.

All multiples of 4 .

Correct option is B

if , g'(z) = f(z), Then

f(z)=g(z)f(z) is given as :f(z)=sinzzpf(z)=zz33!+z55!z2n+1(2n+1)!zp (expanding sin z)Now, Let, p=2Then f(z) becomes,f(z)=sinzzpf(z)=zz33!+z55!z2n+1(2n+1)!z2.log(z) will be present in integration of f(z), so p=2 is not possible, same with p=4 and 6i.eOptions A,C and D are incorrectAlso, if p is odd then  logz won’t be present in integration of f(z)Hence, p can be any odd number\int{f(z)}=g(z)\\\text{f(z) is given as :}\\ f(z)=\frac{sin z}{z^p}\\f(z)=\frac{z-\frac{z^3}{3!}+\frac{z^5}{5!}\cdots\frac{z^{2n+1}}{(2n+1)!}}{z^p}\ (\text{expanding sin z} )\\Now,\ Let,\ p=2\\\text{Then f(z) becomes,}\\f(z)=\frac{sin z}{z^p}\\f(z)=\frac{z-\frac{z^3}{3!}+\frac{z^5}{5!}\cdots\frac{z^{2n+1}}{(2n+1)!}}{z^2}\\.\\\text{log(z) will be present in integration of f(z), so p=2 is not possible, same with p=4 and 6}\\i.e \textbf{Options A,C and D are incorrect}\\\text{Also, if p is odd then }\ logz\ \text{won't be present in integration of f(z)}\\ \textbf{Hence, p can be any odd number}​​

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