Answer
The value of $\cos \left( 256{}^\circ \right)$ is $-0.2419$.
Work Step by Step
Step 1: Open Ti-83.
Step 2: Press $cos$ button.
Step 3: Enter the value like this,
$\cos \left( 256{}^\circ \right)=-0.2419$
The obtained value is $-0.2419$.
Hence the value of $\cos \left( 256{}^\circ \right)$ is $-0.2419$.
