Which of the following are equivalent to the function y = 4cos x - 2?
a. y= 4sin(x-pi/2)-2
b. y=4sin(x+pi/2) - 2
c. y=4cos(-x)-2
d. y=-4cos x +2.
there could be multiple answers too.

option (b) and (c) holds.

Step-by-step explanation:

we are given a function y=4 cos(x)-2

we have to find a function equivalent to the given function.

As we know that cos(-x)=cos(x).

and also sin(π/2+x)=cos(x).

this means that 4 cos(-x)-2=4 cos(x)-2=y

and 4 sin(π/2+x)-2=4 cos(x)-2=y.

Hence the equivalent expression to the given equation is option (b) and (c).

the answer is 13 cm