Please help

1.

Find all the values of a: where the graph of at) = 2:33 42332 + 270.1: 9 has a horizontal tangent line. 3 3 An equation for the line tangent to the graph of y = 4 + + 2 at the point there a: = 415: m m 31:: Let 3(t) = 6t3 + 451*.2 + 108t be the equation of motion for a particle. Find a function for the velocity. \"W = :1 Where does the velocity equal zero? [Hint: factor out the GCE] t = C] m = E] Find a function for the acceleration of the particle. 0 =:1 A ball is thrown upward in the air, and its height above the ground after 15 seconds is H(t) = 8213 16152 feet. Find the time t when the ball will be traveling downward at 20.5 feet per second. Give your answer as a decimal approximation with at least 3 decimal places.