5 . A Is - foot ladder is sliding down a wall, such that the angle between the wall and the ladder is increasing at rate of 5. 73's How fast the ladder sliding down the wall critically, when the virtical distance between the top of the ladder and the ground cy, is 12 feet ? hint : change the unit of the angle ladder wall X ground 6. Determine the inflection points? of y: - 4x 4 - * 3 + 45 x 2 Also state any intervals for which the function is concave up or concave down 6.1 Sketch the function above. Include the inflection points and any maximum / minimum points