- #1
siddscool19
- 5
- 0
Quadratic equation and absolute value...
Consider equation |x2-2x-3|=m, m belongs to R
If the given equation has no solution then find the interval in which the m lies.
2. Homework Equations -Given in question
3.
Since this equation is in modulus there would be two equations:
One is : x2-2x-3=m
Second : x2-2x-3= -m
Discrimant=b2-4ac
Discriminant of 1st equation= 16+4m
Discriminant of 2nd equation= 16-4m
Discrimant for both the equations should be less than 0 (so that the roots are imaginary and there is no solution)
After solving D<0
I get m<-4
and m>4
I would have to take intersection of these equations to get the final answer. But there intersection would be a null set.
But the answer is not null set :(
Please tell me all my mistakes in my solution. Because there are similar problems in which also i am facing problems but since it wouldn't be good to ask all problems I am asking one only. :)
Consider equation |x2-2x-3|=m, m belongs to R
If the given equation has no solution then find the interval in which the m lies.
2. Homework Equations -Given in question
3.
Since this equation is in modulus there would be two equations:
One is : x2-2x-3=m
Second : x2-2x-3= -m
Discrimant=b2-4ac
Discriminant of 1st equation= 16+4m
Discriminant of 2nd equation= 16-4m
Discrimant for both the equations should be less than 0 (so that the roots are imaginary and there is no solution)
After solving D<0
I get m<-4
and m>4
I would have to take intersection of these equations to get the final answer. But there intersection would be a null set.
But the answer is not null set :(
Please tell me all my mistakes in my solution. Because there are similar problems in which also i am facing problems but since it wouldn't be good to ask all problems I am asking one only. :)