Finding Roots of a Complex Equation: Exploring Solutions to cos(z)=2

In summary, the conversation discusses finding all roots or solutions of the equation cos(z)=2, where z is a complex number. The equation is rewritten in terms of the exponential function and z is substituted with its real and imaginary components. The resulting equation is e^{iz} + e^{-iz} = 4, which can be solved for z.
  • #1
buzzmath
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Homework Statement


Find all roots of the equation cos(z)=2 (z is a complex number)

Homework Equations


The Attempt at a Solution


What do they mean find the roots of this equation? We're just going over trig functions and it doesn't say anything about roots so I'm not sure what they're asking for. when I looked on the internet I just kept getting things raised to 1/n. I don't see that all here.
 
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  • #2
Okily well the roots basically means the solutions. We want a z that which, cos z=2 ok?

Write out cos x in terms of the exponential function, (which can be derived from Euler Formula).

[tex]cos x = \frac{e^{ix} + e^{-ix}}{2}[/tex]. Now write z in terms of its reals and imaginarys, z=a + bi. Substitute and get

[tex]e^{iz} + e^{-iz} = 4[/tex]. Hopefully you can work it from there.
 

What are the "roots" of a complex equation?

The roots of a complex equation are the values of the variable(s) that make the equation equal to zero. In other words, they are the solutions to the equation.

How do I find the roots of a complex equation?

To find the roots of a complex equation, you can use the quadratic formula, the rational root theorem, or other methods depending on the type of equation. It is also helpful to use graphing software or a graphing calculator to visualize the roots.

Why do complex equations have multiple roots?

Complex equations can have multiple roots because they involve complex numbers, which have both a real and imaginary component. This allows for more possible solutions compared to equations with only real numbers.

Can the roots of a complex equation be imaginary?

Yes, the roots of a complex equation can be imaginary. This means that they involve the imaginary unit, i, which is the square root of -1. Imaginary roots can also be written in the form a + bi, where a and b are real numbers and i is the imaginary unit.

How can the roots of a complex equation be used in real life?

The roots of a complex equation can be used in various fields of science and engineering, such as physics, electrical engineering, and signal processing. They can also be used in finance and economics to model complex systems and make predictions based on the roots of the equations.

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