Connect with a global community of experts on IDNLearn.com. Get accurate and comprehensive answers from our network of experienced professionals.

Given that [tex]$z=x+iy$[/tex] with [tex]$x, y \in \mathbb{R}$[/tex], calculate [tex]\left|e^{ix}\right|[/tex].

Sagot :

Let's break down the problem step by step to find the magnitude of [tex]\( e^{ix} \)[/tex].

Given that [tex]\( z = x + iy \)[/tex], where [tex]\( x \)[/tex] and [tex]\( y \)[/tex] are real numbers:

1. Euler's Formula:

Euler's formula states that [tex]\( e^{ix} = \cos(x) + i\sin(x) \)[/tex]. This is a fundamental result from complex analysis which allows us to express the exponential function of an imaginary argument in terms of trigonometric functions.

2. Magnitude of a Complex Number:

The magnitude (or absolute value) of a complex number [tex]\( a + ib \)[/tex] is given by [tex]\( \sqrt{a^2 + b^2} \)[/tex]. In our case, the complex number in question is [tex]\( \cos(x) + i\sin(x) \)[/tex].

3. Applying Euler's Formula:

So, using Euler's formula, the complex number [tex]\( e^{ix} \)[/tex] can be represented as [tex]\( \cos(x) + i\sin(x) \)[/tex].

4. Finding the Magnitude:

The magnitude of [tex]\( e^{ix} = \cos(x) + i\sin(x) \)[/tex] is:

[tex]\[ \left| e^{ix} \right| = \sqrt{(\cos(x))^2 + (\sin(x))^2} \][/tex]

5. Using Pythagorean Identity:

From trigonometry, we know the Pythagorean identity which states that [tex]\( (\cos(x))^2 + (\sin(x))^2 = 1 \)[/tex].

6. Final Result:

Therefore, substituting this identity into our magnitude formula, we get:

[tex]\[ \left| e^{ix} \right| = \sqrt{1} = 1 \][/tex]

So, the magnitude of [tex]\( e^{ix} \)[/tex] is always [tex]\( 1 \)[/tex] for any real value of [tex]\( x \)[/tex].

In conclusion, the magnitude [tex]\(\left|e^{ix}\right|\)[/tex] is:

[tex]\[ 1.0 \][/tex]