Which of the following ratios correctly describes the cosine function?

Question

mjdennis · Answer

None of them, until you post them here.

mjdennis · Answer

Sorry, silly joke.  Please be aware that you have only posted half your question.

mathmale · Answer

Weren't there answer choices?

If you're in trig it's essential that you learn and remember the definitions of the basic trig functions.

The top 3 are the sine, the cosine and the tangent.

How are those defined in terms of the names of the 3 sides of a right triangle?

It'd also help you considerably to learn the definitions of the cotangent, secant and cosecant.