Selective serotonin reuptake inhibitor. Selective serotonin reuptake inhibitors (SSRIs), also known as serotonin-specific reuptake inhibitors or serotonergic antidepressants,[1] are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder and anxiety disorders.
Then you're looking for the midpoint! The midpoint of a line segment is the point located midway between the endpoints of the line segment. This tutorial tells you about the midpoint of a line segment.
An alternative technique is the endpoint elasticity formula. The midpoint elasticity formula is a common method of calculating elasticity, especially the price elasticity of demand, price elasticity of supply, income elasticity of demand, and cross elasticity of demand. This formula is most often used at the introductory level of economic instruction.