need help understanding

Exercise 3 - Temperature in a sphere. (dpts total) The temperature T in a plastic ball is inversely proportional to the distance from the center of the ball, which we set to be the origin of the referential (0,0, 0). The temperature at the point (1,2,2) is 1/3. (a) Find the rate of change of T" at (1,2,2) in the direction of the vector v = (2,1, 3). (thsl (b) Explain that at any point in the ball, the direction of the greatest increase in temperature is given by a vector that points towards the origin. (2pts) Here, using o 'wordy' explanation and maybe providing a picture is perfectly fine. Exercise 4 - Lagrange Multipliers. (4pts total) Using the method of Lagrange multipliers, find the area of the largest rectangle, with sides parallel to the coordinate axes that can be inscribed in the ellipse 22 +4y? = 1. Give the coordinates of the corner of the rectangle in the first quadrant