Let $ P_n = \alpha^n + \beta^n $, $ n \in \mathbb{N} $. If $ P_{10} = 123,\ P_9 = 76,\ P_8 = 47 $ and $ P_1 = 1 $, then the quadratic equation having roots $ \alpha $ and $ \frac{1}{\beta} $ is:
It is defined as the movement of heat across the border of the system due to a difference in temperature between system and its surroundings.
Heat can travel from one place to another in several ways. The different modes of heat transfer include: