How do you calculate $cos A= 0.81$ ?

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Answer 1 · 2016-06-07T20:44:56

See explanation.

$cos A = 0.81$

In this problem, we are asked to find the value of $A$ , so that $cos A$ is equal to $0.81$ .

All you need to do is take the inverse of $cos$ and set it equal to $0.81$ .
So:

$cos^-1 = 0.81$
$cos^-1 ~~ 0.63$ (Radians), $35.9$ (Degrees)

So, $A$ can be $0.63 or 35.9$ , depending on which mode you are asked to use.

How do you calculate cos A= 0.81 cos A= 0.81?