Question

Express the following functions as a positive angle:
Cot (-99)
Cos (-140)

Answer 1

\[\cot (-99 {}^{\circ})=\tan (9 {}^{\circ}) \]\[\cos (-140 {}^{\circ})=-\cos (40 {}^{\circ}) \]

Answer 2

\[\cot(-99)=\cos(-99)/\sin(-99)=\cos(99)/-\sin(99) = -\cot(99) \]