• a tractable problem is ‘a problem that can be solved usinga reasonable amount of resources (i.e., time and space)
• common operation costs
• common growth rates
• an asymptotic runtime is a measure of approaching a value or curve (i.e., a runtime expression) arbitrarily closely

$\text{Big - }\mathcal{O}$

$\text{Big - }\Theta$

$\text{Big - }\Omega$