Who can answer the question in the picture ?

Let the closed interval [a , b] be the domain of function f. the domain of f(x - 3) is given by (a) the open interval (a , b) (b) the closed interval [a , b] (c) the closed interval [a - 3 , b - 3] (d) the closed interval [a + 3 , b + 3]

If the value of cos330°is√3/2 then find cos 165°.

Which choice has the correct steps in graphing the solution set to the following inequality? -45_> 20x-5y