Using coterminal angles to evaluate the trigonometric function cosine

The video tutorial explains coterminal angles, focusing on finding the smallest coterminal angle by adding or subtracting multiples of 2π. It demonstrates simplifying angles using revolutions and calculating coterminal angles with examples. The tutorial also covers finding positive angles and using the unit circle, concluding with a cosine calculation of the angle.

What is the purpose of adding or subtracting 2π when dealing with angles?

• To change the angle's quadrant

• To find the smallest coterminal angle

• To convert the angle to degrees

• To determine the angle's sine value

How can you simplify the angle 15π/2 to find a coterminal angle?

• By dividing by π

• By multiplying by 2

• By subtracting 4π/2 multiple times

• By adding 3π

What is the final coterminal angle obtained from 15π/2?

• 7π/2

• 5π/2

• 3π/2

• π/2

What is the cosine of the angle π/2 on the unit circle?

• -1

• 0

• Undefined

• 1

Why is it beneficial to visualize angles on the unit circle?

• To convert the angle to radians

• To easily determine the angle's sine and cosine values

• To identify the angle's quadrant

• To find the tangent of the angle