→ Vulpix :如果你會(1+cosθ)^(1/2),那可寫sinθ成cos(直角-θ) 02/11 17:48
推 susanyen :1+sinθ=(sin(θ/2))^2+(cos(θ/2))^2+2sin(θ/2)cos 02/11 18:33
→ susanyen :(θ/2) = [sin(θ/2)+cos(θ/2)]^2 02/11 18:33
推 Qdream :之前算arc length也是不會積,後來才找到這公式 02/12 13:59
→ cuteboy15 :感謝指導 02/14 15:46