- #1
Ryuk1990
- 158
- 0
Homework Statement
I'm wondering how you would find values of sin, cos, tan, sec, csc, and cot without a calculator. I don't have a specific problem but how would you solve things like tan 45 degrees, sec 30 degrees, and cos -30 degrees?
2. Relevant info
I have the values of sin and cos memorized for 0, 30, 45, 60, 90, 180, and 270 degrees. There is a technique to solving the problems above knowing whether the trig functions are positive or negative in specific quadrants. How is that relevant to solving for the values?
The Attempt at a Solution
I know how to solve some of the above using identities. For example, tan 45 is just sin 45/cos 45 which is 1. For sec 30, I believe it's just 1/cos 45 so it'd be 1/([tex]\sqrt{2}[/tex]/2).
I don't know how to solve cos -30. How would you solve the problems without identities? There is a way knowing when the functions are positive/negative in the quadrants. It also has something to do with adding and subtracting the angle measurement. Can someone explain the technique please?