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Show that f′(z) does not exist anywhere for the following functions.f(z)=2x+xy²i

User Topheman
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Final answer:

To show that f'(z) does not exist anywhere for the given function f(z) = 2x + xy^2i, we need to verify if the function satisfies the Cauchy-Riemann equations.

Step-by-step explanation:

To show that $$f'(z)$$ does not exist anywhere for the given function $$f(z) = 2x + xy^2i$$, we need to verify if the function satisfies the Cauchy-Riemann equations. The Cauchy-Riemann equations state that for a complex-valued function $$f(z) = u(x,y) + iv(x,y)$$ to be differentiable at a point $$z = x + yi$$, the partial derivatives of $$u$$ and $$v$$ with respect to $$x$$ and $$y$$ must satisfy certain conditions.

In this case, the partial derivatives of $$u$$ and $$v$$ are:

$$\frac{\partial u}{\partial x} = 2$$

$$\frac{\partial u}{\partial y} = 0$$

$$\frac{\partial v}{\partial x} = y^2$$

$$\frac{\partial v}{\partial y} = 2xy$$

Since $$\frac{\partial u}{\partial x}$$ is not equal to $$\frac{\partial v}{\partial y}$$ and $$\frac{\partial u}{\partial y}$$ is not equal to $$-\frac{\partial v}{\partial x}$$, the Cauchy-Riemann equations are not satisfied. Therefore, $$f'(z)$$ does not exist anywhere for the given function.

User Smeso
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