1.方程lgx=3-x²的实根所在区间为_______.2.若f(x)为奇函数,且在（0,正无穷）内是增函数,又 f(-3)=0,则xf(x)＜0的解集为________.

1.方程lgx=3-x²的实根所在区间为_______.2.若f(x)为奇函数,且在（0,正无穷）内是增函数,又 f(-3)=0,则xf(x)＜0的解集为________.
1.方程lgx=3-x²的实根所在区间为_______.2.若f(x)为奇函数,且在（0,正无穷）内是增函数,
又 f(-3)=0,则xf(x)＜0的解集为________.

1.方程lgx=3-x²的实根所在区间为_______.2.若f(x)为奇函数,且在（0,正无穷）内是增函数,又 f(-3)=0,则xf(x)＜0的解集为________.
f(x)=lgx-3+x²
f(1)<0
f(2)>0
所以(1,2)
x<0
f(x)>0=f(-3),x>-3
x>0
f(x)<0=f(3),x<3
所以-3