Precalculus Intro to the Unit Circle

PC - Unit Circle Intro 02/19/21

Directions:

Watch the following video and take notes, then answer the questions that follow.

Multiple Choice

What is the radius of the unit circle?

• 0

• 1

• 1/2

• √2/2

Multiple Choice

What are the 3 basic trig functions?

• Sine, cosine, and cotangent

• Sine, cotangent, and cosecant

• Sine, cosine, and tangent

• Cosecant, cosine, and cotangent

Multiple Choice

sinθ is positive in

• the 1st and 2nd quadrants
• the 1st and 3rd quadrants
• the 1st and 4th quadrants
• the 2nd and 3rd quadrants

Multiple Choice

cosθ is positive in

• the 1st and 2nd quadrants

• the 1st and 3rd quadrants

• the 1st and 4th quadrants

• the 2nd and 3rd quadrants

Multiple Choice

If I wanted to find the sine of an angle, what side lengths would I need to know?

• base, hypotenuse

• hypotenuse, adjacent

• opposite, hypotenuse

• adjacent, opposite

Multiple Choice

The cosine of an angle can be calculated by which expression?

• $$\frac{hypotenuse}{adjacent}$$

• $$\frac{opposite}{adjacent}$$

• $$\frac{adjacent}{hypotenuse}$$

• $$\frac{adjacent}{opposite}$$

Multiple Select

$$\tan\left(\theta\right)$$  of an angle,  $$\theta$$ can be expressed as which of the following?

• $$\frac{opposite}{hypotenuse}$$  

• $$\frac{opposite}{adjacent}$$  

• $$\frac{\sin\left(\theta\right)}{\cos\left(\theta\right)}$$  

• $$\frac{hypotenuse}{adjacent}$$