Edexcel Mathematics January 2023 · Paper 1 · Question 11 · ExamRizz

ExamRizzEdexcel MathematicsMathematics

January 2023 · Paper 1 · Question 11 · 7 marks

11. Olog10 V (0, 3)(10, 2.79) t Figure 2 The value, V pounds, of a mobile phone, t months after it was bought, is modelled by V = abt where a and b are constants. Figure 2 shows the linear relationship between log10 V and t. The line passes through the points (0, 3) and (10, 2.79) as shown. Using these points, (a) find the initial value of the phone, (2) (b) find a complete equation for V in terms of t, giving the exact value of a and giving the value of b to 3 significant figures. (3) Exactly 2 years after it was bought, the value of the phone was £320 (c) Use this information to evaluate the reliability of the model. (2) 29

Lesson: Exponential Functions and Their Graphs