For this case, the first thing you should know is that the cotangent is the inverse function of the tangent. We have then: cot (x) = 1 / (tan (x)) Rewriting we have: cot (x) = 1 / ((sin (x)) / (cos (x))) We do double c: cot (x) = cos (x) / sin (x) Answer: cot (x) = cos (x) / sin (x) option 3