求出下列函数图象的对称轴和顶点坐标 (1)y=-x²+2x+5 (2)y=1-4x-1/2x²
问题描述:
求出下列函数图象的对称轴和顶点坐标 (1)y=-x²+2x+5 (2)y=1-4x-1/2x²
答
(1)y=-x²+2x+5 =-(x²-2x+1)+1+5=-(x-1)²+6对称轴是直线x=1,顶点坐标 (1,6)(2)y=1-4x-1/2x²=-1/2(x²+8x)+1=-1/2(x²+8x+16)+8+1=-1/2(x+4)²+9对称轴是直线x=-4,顶点坐标 (-4,...