SAT Subject Test Mathematics Level 1

IMAGINARY AND COMPLEX NUMBERS

There’s a chance you will encounter a question that begins, “If i^2 = −1...,” like
the example below:

RULES OF IMAGINARY NUMBERS

Example 2

Imaginary numbers: To answer an imaginary numbers question like this, you
have to know how to use your i’s. When you’re adding or subtracting, i’s act a

1. If   i^2     =   −1, then    (2  −   3i)^2   =

(A) −5  −   12i

(B) 4   +   6i

(C) 4   +   12i

(D) 5   +   12i

(E) 13  −   6i