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the rate of change of a changing rate




31st march 2010

the above line is the definition of a differential equation

an example is...

the ageing process begins after a person has passed their physical peak

(say 25)

peoples life-spans are, on average, 75 years

over a 50 year period a persons physiology breaks down faster towards the end of their life

the persons ability to maintain, replace, and repair cells or resist invading cells and viruses reduces by 3% in the years 25 to 35 then by a further 7% from 35 to 45 then by 11% during the age of 45 to 55 and then by 30% from 55 to 65 and then finally it reduces a critical 50% between the age of 65 to 75

the rate of change of this changing rate over a fifty year period when written as a fraction is...

one thirty third

one fifteenth

one ninth

one third

one half

as a ratio it is 1:33, 1:15, 1:9, 1:3 and 1:2