A ball is thrown into the air with a velocity of 20 #, its height (in feet) after t seconds is given by H(t) = 20t - 16t2 a Find the instantaneous velocity when t = some value. You will decide on your own particular numerical t-value to solve for. (You must show work using the definition #1 or #2 of a derivative to receive credit.) b. Find the equation of the tangent line to the curve y = 20t - 16t att = some value (same value you chose in part a)