[5] The altitude of a circular cone is 100 inches and decreasing at the rate of 10 inches per second ; and radius of the base is 50 inches and increasing at the rate of 5 inches per second. At what rate is the volume changing ? 2019.03.06…

[4] The equation to the curve is . Find the value of that makes the area equal to . (圖省略) 2019.03.06記 [4] 曲線の方程式がである。 の面積がとなるようなの値を求めよ。 (圖省略) 長方形の面積のを占めるのだから放物線になるはずで、と予想がつく…

[1] （物理學）An object at a distance of 2 inches from a convex lens has its image magnified three times. What is the focal length of the lens?[2] （物理學）What different phenomena would be observed if the following substances be braught …