Math II -- Complex Numbers! Yikes!

Archive SAT Subject Test Preparation
1

<p>If w is a complex number shown in the figure above,
which of the following points could be -iw?</p>

<p>:(</p>

<p>w is in the second quadrant, the answer is in the first quadrant. How would you go about doing this? I don’t think you need to see the picture for answering this one, but if you wanted to, it’s number 50 in the Mathematics Level 2 Test in the Official Study Guide.</p>

2

<p>complex numbers come in the form a + bi, so w = a+bi, remember that i = square root of -1. So when you multiply -i by -a + bi, you get ai -bi^2. bi^2 is equal to -b so the answer is b + ai which is in the first quadrant.</p>