Incorrect calculations by the computer: tan(x) and cot(x)

Example 1. Suppose


$x=\mathrm{39.26990817.}$

Calculate

$\tan (x)$

and

$\cot (x)$

in MATLAB.

Let's just post the picture directly.

).

Thus, the output of MATLAB contains only 4 and 5 correct digits, with error rates of (16-4)/16 = 75% and (16-5)/16 = 68.75% respectively for the significant figures.