a. Find the derivative function f for the function f. b. Determine an equation of the line tangent to the graph of f at (a,f(a)) for the given value of a. f(x) = v5x + 1, a=7 5 a. f'(x) = 21 5x + 1 b. y =A projectile is fired vertically upward into the air, and its position (in meters) above the ground after t seconds is given by the function s(t) = - 4.912 + 30t. a. Find the instantaneous velocity function v (t). b. Determine the instantaneous velocity of the projectile at t = 1 and t= 2 seconds. O A. a. v(t) = 20.2t; b. v(1) = -20.2 m/s, v(2) = - 40.4 m/s O B. a. v(t) = -9.8t+ 30; b. v(1) = - 20.2 m/s, v(2) = - 10.4 m/s O C. a. v(t) = -9.8t+ 30; b. v(1) = 20.2 m/s, v(2) = 10.4 m/s O D. a. v(t) = 20.2t; b. v(1) = 20.2 m/s, v(2) = 40.4 m/sFind an equation of the tangent line at x = a. 2 y 2 , a=4 O A. y= 8x - 8 O B. y= 4x + 16 O C. y= 4x +8 O D. y= 4x - 8