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..