Edexcel Mathematics Sample paper · Paper 2 · Question 5 · ExamRizz

ExamRizzEdexcel MathematicsMathematics

Sample paper · Paper 2 · Question 5 · 4 marks

5. The mass, m grams, of a radioactive substance, t years after first being observed, is modelled by the equation m = 25e–0.05t According to the model, (a) find the mass of the radioactive substance six months after it was first observed, (2) (b) show that d d m t = km, where k is a constant to be found.

Lesson: Exponential Functions and Their Graphs