The number of users on a new social media platform was tracked over several years.
Exactly 4 years after tracking began, the number of users was 42 000.
Exactly 8 years after tracking began, the number of users was 56 000.
Given that the number of users, U U\,U thousand, t t\,t years after tracking began can be modelled by the equation
U2=a+bt2U^2 = a + bt^2U2=a+bt2
where a a\,a and b b\,b are constants,
find the value of a a\,a and the value of bbb.
According to the model, exactly T T\,T years after tracking began, the number of users was 75 000.
Making your method clear,
find the value of TTT, giving your answer to one decimal place.
(Solutions relying entirely on calculator technology are not acceptable.)
Practise Edexcel A Level Maths 10.4 Applications to Modelling with exam-style questions for A Level Maths. 5 questions, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.