1) estimate the function  calculation errors at the point x1 = 3, x2 = 5, if the calculations are performed with float or double or extended data types

2) how many bits are needed so that the calculation error of this function at the point x1 = 1, x2 = 2 is less than 0.1%

Note: Please provide calculations for these 2 problems with exact answers, don't send abstract answers, as i'm willing to dislike and send a spam-report

Thanks for understanding

ex1x2cos(x1x2)