Find the range of values of m for which the quadratic equation
3x² - 6x + m = 0
has no real roots.
Thanks in advance
3x² - 6x + m = 0
has no real roots.
Thanks in advance
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The part under the square root in the quadratic solution is called the discriminant. If the discriminant is less than zero, then you have no answers.
3x^2 - 6x + m = 0
Discriminant: b^2 - 4ac = (-6)^2 - 4(3)(m) = 36 - 12m
Therefore, for no solutions for 3x^2 - 6x + m,
36 - 12m < 0
Subtract 36 from each side.
-12m < -36
Divide by -12. When multiplying or dividing by a negative number in an inequality, you have to reverse the orientation of the inequality.
m > -36/-12
m > 3
So, if m is greater than 3, you have no solutions.
3x^2 - 6x + m = 0
Discriminant: b^2 - 4ac = (-6)^2 - 4(3)(m) = 36 - 12m
Therefore, for no solutions for 3x^2 - 6x + m,
36 - 12m < 0
Subtract 36 from each side.
-12m < -36
Divide by -12. When multiplying or dividing by a negative number in an inequality, you have to reverse the orientation of the inequality.
m > -36/-12
m > 3
So, if m is greater than 3, you have no solutions.
-
3x² - 6x + m = 0
a = 3, b = - 6, c = m
Discriminant = d
d = b² - 4am
For imaginary roots, d < 0, so
b² - 4am < 0
(- 6)² - 4(3)m < 0
36 - 12m < 0
- 12m < - 36
m > - 36 / - 12
m > 3
¯¯¯¯¯
a = 3, b = - 6, c = m
Discriminant = d
d = b² - 4am
For imaginary roots, d < 0, so
b² - 4am < 0
(- 6)² - 4(3)m < 0
36 - 12m < 0
- 12m < - 36
m > - 36 / - 12
m > 3
¯¯¯¯¯
-
Use the discriminant: b^2 - 4ac = (-6)^2 - 4(3)(m) = 36 - 12m
We require 36 - 12m < 0 for no real roots.
Thus 12m > 36 and m > 3
We require 36 - 12m < 0 for no real roots.
Thus 12m > 36 and m > 3
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(−6)² − 4(3)(m) < 0
36 − 12m < 0
−12m < −36
m > 3.
36 − 12m < 0
−12m < −36
m > 3.