explain please

7. Points (1, 4) and (7, 8) are endpoints of the diameter of a circle. (a) What is the exact length of the diameter? (Simplify as much as possible) Answer: (b) What is the center of the circle? Answer: (c) What is the equation of the circle? Answer: \f\fA projectile is launched from a platform 8 feet high with an initial velocity of 40 feet per second, The ght h of the projectile at 1' seconds after launch is given by h = l6t2 + 401? + 8 feet. How many seconds after launch does the projectile attain maximum height? Show work. What is the maximum height? Show work