Answers

2014-10-13T15:36:25+08:00
For the roots to be complex, the discriminant must have a negative value.
having the discriminant as 
 \sqrt{b^2-4ac} or you can just check
b² - 4ac 
where c = m
for the answer to have a negative value, 4ac must be greater than b² 
then you'll have:
4(5)c > (-5)²
20c > 25
c > 5/4
c > 1.25
or
m > 5/4 or 1.25

0