구의 발판곡면(Pedal curved surface of sphere)
구의 발판곡면(Pedal curved surface of sphere) : http://me2.do/5j339ODE YouTube : https://youtu.be/3cmUZXUytxA
수학자료실 강의실 : https://goo.gl/czyJLW YouTube Channel : https://goo.gl/JpzU5i twitter : https://twitter.com/mineungi