Understanding Exact Trigonometric Values

In this video, Lucy introduces two methods to remember exact trigonometric values for specific angles: 0°, 30°, 45°, 60°, and 90°. The first method involves using a table to calculate sine, cosine, and tangent values by dividing by two and applying square roots. The second part, not covered in this video, will demonstrate a hand trick for those who find the table method challenging. The video emphasizes the importance of understanding these values and provides a step-by-step guide to simplify them.

Which angles are focused on in this video for exact trigonometric values?

• 0°, 45°, 90°, 135°, 180°

• 30°, 60°, 90°, 120°, 150°

• 15°, 30°, 45°, 60°, 75°

• 0°, 30°, 45°, 60°, 90°

What is the sine value of 30°?

• 1

• √3/2

• 1/2

• 0

How do you calculate the sine value for these angles?

• Divide by 3 and square root on top

• Multiply by 2 and square root on top

• Divide by 2 and square root on top

• Multiply by 3 and square root on top

What is the cosine value of 60°?

• 1/2

• 0

• 1

• √3/2

How do you calculate the cosine value for these angles?

• Start from three and work down

• Start from two and work up

• Start from four and work down

• Start from zero and work up

What is the tangent value of 45°?

• 0

• Undefined

• √3

• 1

How is the tangent value calculated for these angles?

• Subtract sine from cosine

• Add sine and cosine

• Multiply sine by cosine

• Divide sine by cosine

What happens when you try to calculate tan 90°?

• It equals 1

• It equals 0

• It results in a math error

• It equals √3

What is the alternative method mentioned for remembering trig values?

• Using a hand trick

• Using a chart

• Using a mnemonic

• Using a calculator

What is the main focus of the second part of the video?

• Using a hand trick to remember values

• Understanding the unit circle

• Learning advanced trigonometry

• Exploring trigonometric identities