Among the variations on the graphs of the trigonometric functions are shifts--both horizontal and vertical. Such shifts are easily accounted for in the formula of a given function. Take function f, where f (x) = sin(x) .
The running costs vary from gas to electric. The average running cost for an electric water heater is $550. The average running costs of a gas water heater is $400. The difference in usage price per year is $150.
Hot Water Heater. Expected life: 10 years for gas or electric; 20 years for tankless. Total cost : $548 to $915 for energy-efficient model; $739 to $1,240 for tankless; $2,658 to $3,443 for heat-pump water heater.It's time if: The unit is ten years old or more, leaks around the base, or works erratically.ot Water Heater. Expected life: 10 years for gas or electric; 20 years for tankless. Total cost : $548 to $915 for energy-efficient model; $739 to $1,240 for tankless; $2,658 to $3,443 for heat-pump water heater.