The tangent function is a the ratio for an angle defined as opposite / adjacent. A negative applied to −tan θ will give the opposite value. This is also true for the function when taken on a negative angle. tan(−θ) = −tan θ. This identity is also true for sin, sec, and cot. Recall that cotangent is the reciprocal of tangent and is defined as the ratio adjacent / opposite. Taking the reciprocal of cotangent will be the same as tangent. Using this information the following are equivalent:
1/cotθ
−1/cotθ ----> The reciprocal of Cot is Tan
1/cot(−θ)
----> The reciprocal of Cot is Tan and cot(−θ) = −cot θ.
To calculate this, all we need to do is 150 * 0.125 ≈ 18.75 which rounds to 19. We round to the nearest integer because you can't land on the 4 18.75 times.