题目

已知sinα、cosα是关于x的方程x2-ax+a=0的两个根（a∈R),(1)求sin3θ+cos3θ的值；（2）求tanθ+的值. 答案：解：依题意由Δ≥0,即（-a）2-4a≥0,得a≤0或a≥4且①2+②×2,得a2-2a-1=0,∴a=1-或a=1+(舍）.∴sinθ+cosθ=sinθcosθ=1-.(1)sin3θ+cos3θ=(sinθ+cosθ)(sin2θ-sinθcosθ+cos2θ)=(1-)［1-(1-)］=-2.(2)tanθ+=,∴tanθ+=. ________, I have never seen anyone who’s as capable as John． [　　] A．As long as I have traveled B．Now that I have traveled so much C．Much as I have traveled D．As I have traveled so much