y=x+根号(4-x²)值域我算的[-2√2,2√2],答案是[-2,2√2]
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y=x+根号(4-x²)值域我算的[-2√2,2√2],答案是[-2,2√2]y=x+根号(4-x²)值域我算的[-2√2,2√2],答案是[-2,2√2]y=x+根号(4-x
y=x+根号(4-x²)值域我算的[-2√2,2√2],答案是[-2,2√2]
y=x+根号(4-x²)值域
我算的[-2√2,2√2],答案是[-2,2√2]
y=x+根号(4-x²)值域我算的[-2√2,2√2],答案是[-2,2√2]
答:
y=x+√(4-x²),定义域满足:4-x²>=0,-2<=x<=2
√(4-x²)=y-x>=0,y>=x>=-2
两边平方:
4-x²=y²-2yx+x²
2x²-2yx+y²-4=0
判别式=(-2y)²-4*2*(y²-4)>=0
4y²-8y²+32>=0
y²<=8
-2√2<=y<=2√2
综上所述,-2<=y<=2√2
所以:值域为[-2,2√2]