Need help on math problem!

[Swanny]

Hello all,

I'm taking the ACT tomorrow and my teacher gave me a test from a while ago to take to make sure I know all the concepts. There's only one problem I can't figure out, and I can't reach my teacher. It goes like this:

The following identities are ture whenever x is an angle measure such that 0<x<90: sin x csc x = 1, cos x sec x = 1, and tan x cot x = 1. For x such that 0<x<90 and sin x = 4/5, what is the value of sec x?

1/5
3/5
4/5
5/4
5/3



The main thing I don't know is what csc and sec are. I know cot is cotangent, but I have no idea what the function does. Can anyone help me out?




Thanks,
Swan

 

[Legendary]

sec = 1 / cos
csc = 1 / sin

the answer is 5/3

 

[Turin39789]

csc = cosecant = 1/sin(t)

sec = secant = 1/cos(t)

cot = cotangent = 1/tan(t) = cos(t)/sin(t)

 

[Swanny]

So all you really need to know is that sec is the inverse of cos and that sin^2 + cos^2 = 1. At least that's how I solved it.


Thanks!