Ireally need

a sound wave is modeled with the equation y = 1/4 cos 2 pi/3 theta

a. find the period. explain your method.
b. find the amplitude. explain your method.
c. what is the equation of the midline? what does it represent?

i really need on this one!

Ashopper bought a watermelon a pack of napkins and some paper plates in his state there was no tax on food the tax rate on non-food items is 5% the total for the three items he bought was 825 before tags and he paid $0.19 in taxes how much did the watermelon cost

This question awards 100 ! i really don’t want to fail i will also mark you !

Answer 20 points and brainiest ! on the board, your teacher writes an example of how to find the median. one of the numbers is erased, leaving what is shown, 18, 30, 26,12 22. what is the median? a. 10 b. 20 c. 24 d. 28