How do you calculate the $cos^-1 (-sqrt2/2)$ ?

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Answer 1 · 2015-12-07T03:34:34

Evaluate $cos^-1 (-sqrt2/2)$

Ans: $+- (3pi)/4$

Trig table of special arcs and unit circle -->
$cos x = -sqrt2/2$ --> arc $x = +-(3pi)/4$

How do you calculate the cos^-1 (-sqrt2/2)cos^-1 (-sqrt2/2)?