Personality disorders are a form of mental disorder. They are characterised by a long-term pattern of serious behavioural differences that significantly affect the functioning of the individual in personal and social situations.
Some types of personality disorder that have been defined are:
... formula is derived by the method of completing the square[?].
<math>ax^2+bx+c=0</math>
Dividing our quadratic equation by a, we have
<math>
x^2 ...