tolong please kerjakan

grafik fungsi

a. tabel y = cos 2x
x.....0....π/4 ....π/2....3π/4 ....π
y ....1.....0........-1.......0.........1

b. HPB (x,y)= (0,1), (π/4 , 0). (π/2, -1) , (3π/4 , 0). (π, 1)
grafik di lampiran
c.
periode = 2π/|2| = π
Maksimum = 1
minimum = - 1