1. ## imaginary numbers

what kind of variable would you use to represent these?

2. an imaginary one?

3. is there a type of variable you could use to represent them? i dont really know a lot about imaginary numbers and i need to use them in a program i have to write

4. not that i can remember, but what is stopping you from creating your own class to represent imaginary numbers?

5. ok you got me.......i feel like an idiot but what exactly is an imaginary number?

6. std::complex maybe?

For imaginary numbers only i suppose you could set the real part to zero. Ive only used i as part of a complex number never alone.

7. I think the proper way to think about it is that an imaginary number is a complex number that isn't a real number, so it is always a complex number, regardless if the real part of it is zero or not.

...edit...

maybe not, the FAQ above explains:

"Imaginary numbers are numbers that can be written as a real number times i."

"Complex numbers are numbers like 7 + .4i; they're a real number plus an imaginary number."

8. ok i get what imaginary numbers are now. i have to write a program that solves the quadratic formula and i need to include imaginary numbers in the program......what do these numbers have to do with solving the quadratic formula?

9. Think of this. The square root of a negative number has to be imaginary. So
y=4a+3b+4 would be written.
Code:
```(-3(+/-)(sqrt((squared(3))-(4*4*4))))/(4*2)

assume #define squared(x) x*x```
Use what you learned in those tutorials to figure out how you would evaluate the problem above.

10. The quadratic formula will tell you the two roots of the equation. For example, for the quadratic y = x^2 - 1, the graph would intersect the x-axis at -1 and 1. These are the roots. If the graph were y = x^2 + 1 on the other hand, there would be no real roots because the graph of the quadratic doesn't intersect the x-axis. In this case you would have two imaginary roots, -i and i. We get this from the quadratic formula:

-b +/- sqrt( b^2 -4(a)(c)) / 2a
=
+/- sqrt(-4) / 2 = +/- 2i / 2 = +/- i
(remember i is the sqrt(-1))

I'm a beginner at programming myself, so I don't know which header it is that has support for complex numbers, but this is why you would need them.

Extol: remember that in your example, 4, 3, and 4 are equal to a, b, and c. I believe you want x's where you have your a and b

11. so to declare an imaginary number......i could just do this right?

double i = sqrt(-1);

12. Oh gosh. Yea, isn't it 4x^2+3x+4 even. I don't remember.

13. alright i think i actually need to use complex numbers......is therea way to declare these?