Math Problem Statement

Express 1 + i in polar form.

Solution

The question in the image asks to express 1+i1 + i in polar form.

To express a complex number z=a+biz = a + bi in polar form, we use the formula:

z=r(cosθ+isinθ)z = r(\cos \theta + i \sin \theta) where:

  • rr is the magnitude of the complex number,
  • θ\theta is the argument (or angle) of the complex number.

For the complex number 1+i1 + i:

  • The real part a=1a = 1,
  • The imaginary part b=1b = 1.

Step 1: Find the magnitude rr

The magnitude rr is given by:

r=a2+b2r = \sqrt{a^2 + b^2}

Substitute a=1a = 1 and b=1b = 1:

r=12+12=2r = \sqrt{1^2 + 1^2} = \sqrt{2}

Step 2: Find the argument θ\theta

The argument θ\theta is the angle that the complex number makes with the positive real axis. It can be found using the formula:

θ=tan1(ba)\theta = \tan^{-1} \left( \frac{b}{a} \right)

For a=1a = 1 and b=1b = 1:

θ=tan1(11)=π4\theta = \tan^{-1} \left( \frac{1}{1} \right) = \frac{\pi}{4}

Final Answer:

So, the polar form of 1+i1 + i is:

z=2(cosπ4+isinπ4)z = \sqrt{2} \left( \cos \frac{\pi}{4} + i \sin \frac{\pi}{4} \right)

Let me know if you would like more details or if you have any questions!

Related Questions:

  1. How do you convert from polar to rectangular form?
  2. Can polar form be used for any complex number?
  3. What is the general formula for converting to polar form?
  4. How do you find the argument of a complex number in different quadrants?
  5. What are the applications of polar form in mathematics?

Tip:

The magnitude rr always represents the distance of the complex number from the origin in the complex plane!

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Math Problem Analysis

Mathematical Concepts

Complex Numbers
Polar Coordinates

Formulas

Magnitude r = √(a² + b²)
Argument θ = tan⁻¹(b/a)
Polar form z = r(cosθ + i sinθ)

Theorems

Polar form of complex numbers

Suitable Grade Level

Grades 10-12