Given that cos(alpha)=1/5 and 0< alpha< pi/2, determine the values of cos alpha/2

Which math sentence can be used to determine if the triangle is a right triangle?

Angela is buying a dress that is on sale for 20% off. if the original price of the dress is $40.00, how much money is angela saving on the dress? a. $0.80 b. $3.20 c. $32.00 d. $8.00

Which equation represents the function on the graph?