Trigonometry
posted by steve
complex numbers

Reiny
They must be imaginary, I don't see them

Steve
just as real numbers can be located on the number line, complex numbers can be located in the plane, because they have a real part and an imaginary part. So,
a+bi
is located in the plane by a pair of coordinates: a units along the horizontal axis, and b units vertically from there.
Not sure how a long discourse here will be any more useful than the discussion in your text. Or, do a web search, and you will find many articles explaining them. 
Steve
The reason they come up in trig is that any point in the plane can be located at some distance from the origin, and in some direction, given by an angle θ. All your normal trig functions can be applied to θ.
Respond to this Question
Similar Questions

Math
I am in the 5th grade and my homework tonight is about complex numbers. I have no idea how to do complex numbers, not to mention, I don't know what they are. Can you help me? 
Math (Complex Numbers)
Let a,b,c be complex numbers satisfying a+b+c=abc=1 and (ab+bc+ac)/3=(1/a^2)+(1/b^2)+(1c^2) The sum of absolute values of all possible ab+bc+ac can be written as (√n)/m, where n and m are positive coprime integers. What is n+m? 
mathcomplex numbers
Sketch the sets of complex numbers in the complex plane that satisfy the following: a) z1=2 b) z3i=2 c) z5+2i=2 I'm not sure, but are you supposed to rearrange the whole thing to z=a+bi? 
Precalculus
Let z and w be complex numbers such that 2z  w = 25, z + 2w = 5, and z + w = 2. Find z. I need a little help with absolute values on complex numbers. 
Precal
The equation of the line joining the complex numbers 5 + 4i and 7 + 2i can be expressed in the form az + b*overline{z} = 38 for some complex numbers a and b. Find the product ab. Any help? 
Complex Numbers
Let z and w be complex numbers such that z = w = 1, and zw is not equal to 1. Prove that (z + w)/(zw + 1) is a real number. 
Complex Numbers
Let z and w be complex numbers such that z = w = 1, and zw is not equal to 1. Prove that (z + w)/(zw + 1) is a real number. 
Precalc
To which set(s) of numbers does the number sqrt 16 belong? 
Math... with complex numbers
Complex numbers are often used when dealing with alternating current (AC) circuits. In the equation V = IZ, V is voltage, I is current, and Z is a value known as impedance. If V = 1+i and Z=2$, find I. 
Math (Complex Numbers)
how does one go about solving something such as: conjugate(z+23i) = z+5+10i Conjugates of actual complex numbers are very simple, but the inclusion of z trips me up