Sin(a-30)-sin(a+30)=-coss​

Suppose investors can earn a return of 2% per 6 months on a treasury note with 6 months remaining until maturity. the face value of the t-bill is $10,000. what price would you expect a 6-month maturity treasury bill to sell for? (round your answer to 2 decimal places. omit the "$" sign in your response.)

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?  

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36