Question 3, I am very confused.

AB = 19

AD = 38

Step-by-step explanation:

It appears that C is the midpoint of BD, so because of that we know that BC and CD are equal. If CD is 9.5, then BD is also 9.5

If B is the midpoint of AD, then we know that AB and BD are equal. So, we can first find the length of BD by adding BC and CD, which equals 19. BD = 19

Because AB = BD and BD = 19, we know that AB would also equal 19.

AB = 19

Then you can just add AB + BD to get AD

19 + 19 = 38

Hope this helps! I apologize if I get this answer incorrect.

since no one answered yet i will give it a shot, not completely sure tho.

i think it should be y=cos(x+2pi), (third answer, answer c)

good luck.