Need help with trig!!

a) sin x

b) cos² x

c) sin²x

Step-by-step explanation:

Step(i):-

Given that the trigonometric equation

we have to use trigonometric formulas

now

                       =

                       =

                      =

Step(ii):-

                                =

                               =

                               =

                               =

                               = sinx

f(x) = x^3 -2x^2 -3x

x( x^2 -2x-3)

x( x^2 +x -3x -3)

x( x(x+1) -3(x+1))

x( x-3)( x+1)

so zeroes are 0, 3,-1

its (2) option

b

step-by-step explanation:

the word superfluous means unnecessary