Me
i know the answer is "c" but i can explain why. can you explain it for me

Will you chech and finish these for me, because i am stumped with them.

Determine the maximum r-value of the polar equation r =3+3 cos 0

When considering gravity acceleration and the force of acceleration, what must be true? a. the direction of acceleration must be perpendicular to the direction of the force. b. the direction of the force and the direction of acceleration must be the same as each other. c. the direction of the force and the direction of acceleration must be opposite of each other. d. the mass of the body must be the same as the acceleration of the body.