Apoint on the unit circle lie on the terminal side of an angle in standard position quadrant iv.

Step-by-step explanation:

The problem is about a vector which is in quadrant IV, that is, its angles if from quadrant I to quadrant IV, this means that such angle is between 180° and 270°, because that's the range of angles placed on quadrant IV.

According to trigonometric function theory, in that quadrant, the cosine function of the angle is positive and the sine function of the angle is negative. This is because in the quadrant IV the independent variable is positive and the dependent variable is negative. The independent variable represents the cosine, and the dependent represents the sine.

Therefore, the complete sentences are

Question 2 answer is 4        Question 3 answer is 12

Step-by-step explanation:

Question 2: 42*4=168

43*5=210