Why won't anyone answer this?

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

The amount spent on food and drink by 20 customers is shown below what is the modal amount spent and the median? 40 25 8 36 18 15 24 27 43 9 12 19 22 34 31 20 26 19 17 28

If sin(x) = 0 and cos(x) = 1, what is tan(x)?