19 is what percent of 95 (need to show how I got the answer)

Aschool puts on a play. the play costs $1,200 in expenses. the students charge $4.00 for tickets. there will be one performance of the play in an auditorium that seats 500 people. what is the domain of the function that shows the profit as a function of the number of tickets sold?  

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)

Which equation represents h for right triangle abc