# secant / cosine functions

• May 6th 2010, 09:51 PM
kevin11
secant / cosine functions
I know this may seem pretty basic but I really don't understand how to estimate these values. I need to know more about the process than just the answers, thanks!

sec 67.43 = ?

If csc θ = 3.164, then θ=?
• May 6th 2010, 10:44 PM
Quote:

Originally Posted by kevin11
I know this may seem pretty basic but I really don't understand how to estimate these values. I need to know more about the process than just the answers, thanks!

sec 67.43 = ?

If csc θ = 3.164, then θ=?

hi

are you allowed to use the calculator ?

sec 67.43 = 1/ (cos 67.43) = 1/0.3838 = 2.61

csc θ = 1/ sin θ

sin θ = 1/3.164 = 0.316

θ = arc sin 0.316 (Press shift , then cos 0.316 )
• May 6th 2010, 11:29 PM
kevin11
ok thanks for your reply, and yes we are allowed to use calculators. But I'm not sure what you mean by 'θ = arc sin 0.316 (Press shift , then cos 0.316 )'. is that the sin with the little -1 (sin^-1(0.316))?

Also, is there a way to express this in terms of pi?
• May 6th 2010, 11:40 PM
Quote:

Originally Posted by kevin11
ok thanks for your reply, and yes we are allowed to use calculators. But I'm not sure what you mean by 'θ = arc sin 0.316 (Press shift , then cos 0.316 )'. is that the sin with the little -1 (sin^-1(0.316))? Yes

Also, is there a way to express this in terms of pi?

To express in terms of pi , you have to convert something in degrees to radian form and it can be done by multiplying pi/180

say to convert 30 degrees to rad form ,

30 x pi/180 = pi/6
• May 6th 2010, 11:47 PM
kevin11
Cool thanks. I didn't realize 1/sin had to be done first before using the arc sin. Probably will have more probs tomorrow, thanks again!