Answer Happy

Object Height. Suppose an object is thrown straight up from the ground. The height after t seconds is given by the formula h(t) = -3t3 + 90t² + 205 (a) The time in seconds when the object reached the highest point was Note: Round to 4 digits after the decimal point, if rounding is required 205 s O 20 s Os 15 s O None of the other answers 45 s (b) The height is maximized at the critical point x = a because the second derivative test found Of"(a) = 0 O f'(a) = 0 O f'(a) was negative to the left of x = a and positive to the right f"(a) < 0 O f'(a) was positive to the left of x = a and negative to the right f"(a) > 0