y 6 4 cos4x pi2 pi2 x piSolutiony 6 4cos4x pi2 pi2

y = 6 - 4 cos(4x+ pi/2), -pi/2 x pi

y = 6 -4cos(4x +pi/2)

-pi/2 <= x<= pi

Lets find xy values for some point of x

Period of the function = 2pi/4 = pi/2

So, x= -pi/2 ; y= 6 -4*cos( -2pi+pi/2) = 6+0 =6

x= -pi/4 ; y= 6 - 4cos( -pi +pi/2) = 6 - 4*0 =6

x= pi/8 ; y= 6 -4cos(- pi/2 +p/2) = 6 -4*1 = 2

x = 0 ; y = 6- 4*cos(pi/2) = 6

x= pi/8\'; y= 6 -4cos( pi/2 +pi/2) = 6 -4*-1 = 10

x= pi/4 ; y = 6- 4cos( pi +pi/2) = 6 -4*0cc=6

x= pi/2 ; y= 6 -4cos( 2pi +pi/2) = 6

x= 5pi/8 ; y= 6 -4cos(5pi/2 +pi/2) = 6- 4cos(3pi) = 10

x = 6pi/8 ; y= 6-4cos(6pi/2 +pi/2) = 6 -4*0 = 6

x = pi ; y= 6- 4cos(4pi +pi/2) = 6 -0 =6