How do you evaluate $cot (cos^-1(-0.7003))$ ?

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Answer 1 · 2016-08-31T14:56:18

$- .981830523$ , nearly

Let $a = cos^(-1)(-.7003) in Q2$ , for principal value. In Q2, cotangent

is positive.

The given expression is

$cot a$

$= cos a/sin a$

$= -.7003/sqrt(1-(-.7003)^2)$

$=- .981830523$ , nearly..

Had we allowed other values of a in Q3,, wherein cot a is positive,

$cot a=.981830523$ , nearly..

How do you evaluate cot (cos^-1(-0.7003))cot (cos^-1(-0.7003))?