17.以10端銑刀銑削圓弧溝槽，尺寸如下圖，若程式為G90G00XαYβ;G01Z-3.0F50;G9 1G17G02XγYδR30.0;則(A)α=11.481,β=-27.716,γ=11.481,δ=27.716(B)α=-11. 481,β=27.716,γ=22.962,δ=0(C)α=11.481,β=-27.716,γ=22.962,δ=27.716(D)α=- 11.481,β=27.716,γ=11.481,δ=0。(sin22.5°=0.38268,cos22.5°=0.92388,tan22.5°=0. 41421)