How do you find the exact value of cot(arcsin(-12/13))?

1 Answer
Dec 29, 2016

cot(arcsin(-12/13))=color(green)(-5/12)

Explanation:

Remember that the arcsin function is defined as having a range (-pi/2,+pi/2]

The arcsin(-12/13) can be represented by a triangle in the standard position with opposite side (i.e. y coordinate): (-12)
and hypotenuse (13)

Based on the Pythagorean Theorem, this triangle would have an adjacent side with the length sqrt(13^2-(-12)^2) =5

Since cot="adjacent"/"opposite"

cot(arcsin(-12/13))=5/(-12)=-5/12