Question

Which complex number has a distance of StartRoot 17 EndRoot from the origin on the complex plane?

2 + 15i
17 + i
20 – 3i
4 – i

Answer 1

d) 4-i

Explanation:

on edge

Answer 2

4 - i

Explanation:

Intuitively, the answer will be 4 - i, as the other numbers are too big to have a square as small as 17i. Also, we know that i will not be in the end result, which means that we should have a negative in the result as well.

To test this, we can simply treat 4 and -i as the sides of a right triangle and find the hypotenuse:

`d = √(4^2 + (-i)^2) \\d = √(16 + 1)\\d = √(17)`

So indeed the answer is 4 - i