Question

An oven heating element turns on when the internal temperature falls to 20 degrees below the set temperature and turns off when the temperature reaches 5 degrees above the set temperature. You preheat the oven to 405 degrees before putting a cake in and baking it for an hour at 405. Write an inequality in terms of the temperature, T, that describes the temperature range of the oven while the cake is baking.

Answer 1

The range of the oven is
`385\leq T\leq 410`

Explanation:

Consider the provided information.

The internal temperature falls to 20 degrees below the set temperature and turns off when the temperature reaches 5 degrees above the set temperature.

You preheat the oven to 405 degrees before putting a cake in and baking it for an hour at 405.

The internal temperature falls to 20 degrees, therefore the lowest set can be:

405-20=385 degree.

The temperature reaches 5 degrees above the set temperature 405, therefore the upper set is: 405+5=410 degree.

Hence, the temperature will be lying between 385 degree and 410 degree.

This can be written as:
`385\leq T\leq 410`

Hence, the range of the oven is
`385\leq T\leq 410`