a, b, c, d, e and f are positive real numbers with the property that maths equation.
What is the smallest possible value of maths equation
Does the diagram below help you?
Geometrically, the sum maths equation is the total length of the six line segments from (0,0) to (20,21). This total length is minimised when the line segments line up (see diagram below), so that the total length is maths equation
.
By Chris Luke