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a. For the function and point below, find f'(a). b. Determine an equation of the line tangent to the graph of fat (a,f(a)) for the given value of a. f(x) = 4x +3x, a= -1 a. f (@) = b. y=A ball is thrown vertically upward from the ground at a velocity of 96 feet per second. Its distance from the ground at t seconds is given by s(t) = - 16t- + 96t. (a) How fast is the object moving 2 seconds after being thrown? (b) When will it hit the ground? (c) What is its velocity upon impact? (a) Find the function v(t) that gives the ball's velocity at time t. v(t) = The ball's velocity at 2 seconds is feet per second. (Type an integer or a decimal.) (b) It takes the ball second(s) to reach the ground. (Type an integer or a decimal.) (c) Upon impact, the velocity of the ball is feet per second. (Type an integer or a decimal.)