Edexcel Mathematics Specimen paper · Paper 2 · Question 3 · ExamRizz

ExamRizzEdexcel MathematicsMathematics

Specimen paper · Paper 2 · Question 3 · 4 marks

3. A cup of hot tea was placed on a table. At time t minutes after the cup was placed on the table, the temperature of the tea in the cup, θ °C, is modelled by the equation θ = 25 + Ae–0.03t where A is a constant. The temperature of the tea was 75 °C when the cup was placed on the table. (a) Find a complete equation for the model. your answer in minutes to one decimal place. (b) Use the model to find the time taken for the tea to cool from 75 °C to 60 °C, giving Two hours after the cup was placed on the table, the temperature of the tea was measured as 20.3 °C. Using this information, (c) evaluate the model, explaining your reasoning

Lesson: Exponential Functions and Their Graphs