Reference Angle Section Question

[hiroze]

This question is in the exercises associated with reference angles. I understand the reference angle part, but there is a question, which I don't know how to work with or without a calculator.

Approximate to three decimal places:
a) sin 73deg 20'
b) cos 0.68

The answers are a) .958 and b) .778 though I don't know where to start. I don't know what the 20' means either.

I looked through the web for some info and the purplemath sections, but I can't get it to work out

[stapel_eliz]

I don't see any way to use reference angles for these...?

To learn about the "degrees, minutes, seconds" notation, try here. Your calculator should be able to handle this notation; check the manual for how to enter the information.

To find these sine and cosine values, you'll either need to use a calculator and round, or else work from trig tables in your book. Look in your text to see how it did similar exercises, and follow that lead.