Trigonometric Functions and Reference Angles

The video tutorial by the Math Sorcerer from Chegg covers the evaluation of trigonometric functions using reference numbers. It explains how to find reference numbers and use them to evaluate cosine, sine, and tangent for angles like 2π/3, 5π/6, 7π/4, and 4π/3. The tutorial emphasizes the importance of drawing sketches and understanding the unit circle, while also providing tips for memorizing key trigonometric values.

What is the main topic discussed in the video?

• Algebraic equations

• Geometry theorems

• Trigonometric functions of real numbers

• Calculus derivatives

What is the first step in solving trigonometric problems using reference numbers?

• Memorizing all trigonometric values

• Drawing a sketch of the angle

• Using a calculator

• Guessing the answer

How do you find the reference number for an angle?

• By using a formula

• By using a calculator

• By drawing a picture and finding the shortest distance to the x-axis

• By memorizing all angles

What is the cosine of pi over three?

• 1

• 0

• -1/2

• 1/2

Why is the cosine of two pi over three negative?

• Because it is in the positive y-value territory

• Because it is in the negative x-value territory

• Because it is in the positive x-value territory

• Because it is in the negative y-value territory

What is the reference number for five pi over six?

• Pi over six

• Pi over three

• Pi

• Pi over four

What is the sine of pi over six?

• 1

• 0

• 1/2

• -1/2

Why is the sine of five pi over six positive?

• Because it is in the negative y-value territory

• Because it is in the positive y-value territory

• Because it is in the negative x-value territory

• Because it is in the positive x-value territory

What is the reference number for seven pi over four?

• Pi

• Pi over four

• Pi over three

• Pi over six

What is the tangent of pi over four?

• 0

• 1

• -1

• Undefined