For a particular angle theta, the cosine function f(x)=a cos b(theta) has the following values within one cycle of the function: f(0)=4; f(pi/4)=0; f(pi/2)=-4; f(3 pi/4)=0; f(pi)=4 what is the rule for the cosine function? a. y=2 cos 4theta b. y=4 cos 2theta c. y=-4 cos 3theta d. y=1/4 cos 2theta

The rule for the cosine function is:

                  B)    

Step-by-step explanation:

We are given the property of angle theta as follows:

Also, we will check by keeping these conditions in each of the given options.

A)

when θ=0 we have:

Hence, option: A is incorrect.

C)

when θ=0 we have:

Hence, option: C is incorrect.

D)

when θ=0 we have:

Hence, option: D is incorrect.

B)

when θ=0 we have:

and similarly the other conditions also gets satisfied.

       Hence, option: B is the correct answer.

answer: 180

step-by-step explanation:

12-2=10

20-2=18

10x18=180