Skip to main content
Back

The Imaginary Unit quiz

Control buttons has been changed to "navigation" mode.
1/15
  • What is the imaginary unit, and what is its value?
    The imaginary unit is denoted as i, and its value is the square root of -1.
  • How do you write the square root of -1 using the imaginary unit?
    The square root of -1 is written as i.
  • How do you simplify the square root of a negative number, such as -b?
    You write it as i times the square root of the positive number, or i√b.
  • What is the simplified form of √(-4)?
    The simplified form is 2i.
  • How do you write the answer when you have a whole number and the imaginary unit?
    Write the whole number first, then the imaginary unit, for example, 2i.
  • What is the simplified form of √(-17)?
    The simplified form is i√17.
  • When simplifying √(-32), what is the final answer?
    The final answer is 4i√2.
  • Why do we use the imaginary unit i?
    We use i to evaluate the square roots of negative numbers, which are not real.
  • What is the general form for the square root of any negative number?
    The general form is i times the square root of the positive number, or i√b.
  • How should you write your answer if it includes both a whole number and a radical with i?
    Write the whole number first, then i, then the radical, such as 4i√2.
  • What do you call numbers that include the imaginary unit i?
    Numbers that include i are called imaginary numbers.
  • Why shouldn't you write √17i instead of i√17?
    Writing √17i is confusing because it's unclear if i is under the radical; write i√17 instead.
  • What is the value of i squared (i^2)?
    i squared equals -1.
  • If you have √(-b), and b is positive, how do you express it using i?
    Express it as i√b.
  • What is the first step in simplifying the square root of a negative number?
    Factor the negative number as -1 times the positive number, then use i for √(-1).