4
QuizMultiple Choice
Unit Test
Question 4 of 18 • CA-Common Core Algebra II B
A student is given that point P(a, b) lies on the terminal ray of angle , which is between radians and 2 radians. The student uses the steps below to find cos . Step 1Find the quadrant in which P(a, b) lies:P(a, b) is in Quadrant IV.Step 2Use the point and the Pythagorean theorem to determine the value of r:, but since r must be positive, .Step 3Determine cos ., where a and b are positive.Which of the following explains whether the student is correct?
Answer
A
The student made an error in step 3 because a is positive in Quadrant IV; therefore, .
B
The student made an error in step 3 because .
C
The student made an error in step 2 because r is negative in Quadrant IV; therefore, .
D
The student made an error in step 2 because using the Pythagorean theorem gives .