Answer:
Interval notation for m: (-3,3)
Inequality notation: -3<m<3
In words: Anything between -3 and 3 without including either -3 or 3.
Explanation:
If we want no real roots then b^2-4ac must be less than 0.
a=1
b=2m
c=9
These values were found by comparing your equation to ax^2+bx+c=0.
b^2-4ac<0 is what we are trying to satisfy
(2m)^2-4(1)(9)<0
4m^2-36<0
Divide both sides by 4:
m^2-9<0
Add 9 on both sides:
m^2<9
m^2<9 when m<3 and m>-3.
Interval notation (-3,3).