Answer Happy

A bison is charging across the plain one morning. His path takes him to location (x,y) at time t, where x and y are functions of t, and north is in the direction of increasing y. The temperature is always colder farther north. As time passes, the sun rises in the sky, sending out more heat, and a cold front blows in from the east. At time t the air temperature H near the bison is given by H=f(x,y,t). The chain rule expresses the derivative dH/dt as a sum of three terms: dtdH​=∂x∂f​∂t∂x​+∂y∂f​∂t∂y​+∂t∂f​. Identify the term that gives the contribution to the change in temperature experienced by the bison that is due to: 1. The coming cold front A. ∂x∂f​∂t∂x​ 2. The rising sun B. ∂y∂f​∂t∂y​ 3. The bison's change in latitude C. ∂t∂f​