Trig Refresher - Pre-Calc Morris

Multiple Choice

Do Now: What is $$\frac{2\pi}{3}$$   radians in degrees? 

• $$150\degree$$  

• $$120\degree$$  

• $$180\degree$$  

• $$30\degree$$  

Multiple Choice

What is $$270\degree$$  in radians?

• $$\frac{\pi}{4}$$

• $$\frac{3\pi}{2}$$

• $$\frac{3\pi}{4}$$

• $$\frac{\pi}{2}$$

Open Ended

What do you know about special right triangles?

Multiple Choice

What is the value of sin (60º)?

• 1/2
• √3/2
• 1/√2

Poll

How comfortable are you with the unit circle?

• I don't remember it at all.

• I remember some of it, but I don't know how to use it.

• Pretty comfortable.

• I remember everything and can teach it to someone.

Open Ended

To find $$\sin\left(150\degree\right)$$ using the unit circle, we need to use reference angles. Do you remember how to find the reference angle? If so, how?

Fill in the Blank

To find $$\sin\left(150\degree\right)$$ first we need to find the reference angle, which is _______.

Next we need to apply the trig function to the reference angle. (use the special triangles or the unit circle.

Finally, apply the appropriate sign ( + or - )

Open Ended

Does anyone have a way of remembering the reference triangles, unit circle, or the reference angle chart?

Multiple Choice

Find the value of $$\cos\left(\frac{5\pi}{6}\right)$$

• $$-\frac{\sqrt{3}}{2}$$

• $$\frac{\sqrt{3}}{2}$$

• $$\frac{1}{3}$$

• $$\frac{1}{2}$$

Multiple Choice

Find the value of $$\tan\left(225\degree\right)$$

• √2/2
• -√2/2
• 1
• -1