Question

函数y=-x^2-2x+3的值域是_______,单调递增区间是_______.

Answer 1

y=-(x+1)^2+4<=4
值域是（-无穷，4]
对称轴是X=-1，开口向下。单调增区间是（-无穷，-1]

Answer 2

y=-x^2-2x+3
=-(x^2+2x+1)+3+1
=-(x+1)^2+4<=4
所以
函数y=-x^2-2x+3的值域是_(-∞,4]____,单调递增区间是_x<=-1