2
QuizMultiple Choice

Multiply and Divide Complex Numbers — Quiz

Question 2 • Math 4

For z is equal to negative 3 minus 5 i , which graph shows z and the product of z times i ?

Answer
A
Image with description Complex plane with the horizontal axis labeled real and the vertical axis labeled imaginary. The x-axis is labeled from negative 6 to 6 in increments of 2, and the y-axis is labeled from negative 6 to 6 in increments of 2. Point z is plotted at (negative 3 comma negative 5). Point z times i is plotted at (3 comma negative 5).
B
Image with description Complex plane with the horizontal axis labeled real and the vertical axis labeled imaginary. The x-axis is labeled from negative 6 to 6 in increments of 2, and the y-axis is labeled from negative 6 to 6 in increments of 2. Point z is plotted at (negative 3 comma negative 5). Point z times i is plotted at (negative 5 comma 3).
C
Image with description Complex plane with the horizontal axis labeled real and the vertical axis labeled imaginary. The x-axis is labeled from negative 6 to 6 in increments of 2, and the y-axis is labeled from negative 6 to 6 in increments of 2. Point z is plotted at (negative 3 comma negative 5). Point z times i is plotted at (negative 3 comma 5).
D
Image with description Complex plane with the horizontal axis labeled real and the vertical axis labeled imaginary. The x-axis is labeled from negative 6 to 6 in increments of 2, and the y-axis is labeled from negative 6 to 6 in increments of 2. Point z is plotted at (negative 3 comma negative 5). Point z times i is plotted at (5 comma negative 3).

Explanation

Multiply each term by i: (−3 − 5i)i = −3i − 5i². Since i² = −1, this becomes 5 − 3i, which has real part 5 and imaginary part −3. So z × i is plotted at (5, −3), matching choice D.

AI-written and checked against the verified answer.

Previous
Next