函數(shù)f(x)的定義域是[1,4]，則函數(shù)f(x^2)的定義域是___________

熱心網(wǎng)友

[1,2]U[-2,-1]解：f(x)的定義域是[1,4]知 f(x)中 1<=x<=4 即f(x^2)中 1<=x^2<=4 即f(x^2)中 1<=x<=2或-2<=x<=-1

熱心網(wǎng)友

1≤x^2≤4 == 1≤|x|≤2 == -2≤x≤-1 or 1≤x≤2函數(shù)f(x)的定義域是[1,4]，則函數(shù)f(x^2)的定義域是:[-2,-1]∪[1,2]。