How do you find the exact value of cot(arcsin(-12/13))cot(arcsin(1213))?

1 Answer
Dec 29, 2016

cot(arcsin(-12/13))=color(green)(-5/12)cot(arcsin(1213))=512

Explanation:

Remember that the arcsinarcsin function is defined as having a range (-pi/2,+pi/2](π2,+π2]

The arcsin(-12/13)arcsin(1213) can be represented by a triangle in the standard position with opposite side (i.e. yy coordinate): (-12)(12)
and hypotenuse (13)(13)

Based on the Pythagorean Theorem, this triangle would have an adjacent side with the length sqrt(13^2-(-12)^2) =5132(12)2=5

Since cot="adjacent"/"opposite"cot=adjacentopposite

cot(arcsin(-12/13))=5/(-12)=-5/12cot(arcsin(1213))=512=512