若抛物线y=-x^2+2(m+1)x+m+3与x轴有两个交点,则m的取值范围是

抛物线y=-x^2+2(m+1)x+m+3与x轴有两个交点⊿=[2(m+1)]²-4×(-1)×(m+3)＞0(m+1)²+4(m+3)＞0m²+2m+1+4m+12＞0m²+6m+13＞0(m²+6m+9)+4＞0(m+3)²+4＞0∴抛物线y=-x^2+2(m+1)x+m+3与x轴有...