Skip to content

Course home

Sign up

Exponentials and Logarithms

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111
Question 81

The temperature, θ∘C\theta^\circ\text{C}θ∘C, of a cup of tea t t\,t minutes after measurements began, is modelled using the formula θ=60e−0.2t+20,t≥0\theta = 60e^{-0.2t} + 20, t \geq 0θ=60e−0.2t+20,t≥0

a.

Sketch the graph of θ \theta\,θ against ttt.

[2]
b.

Find according to the model the initial temperature of the tea.

[1]
c.

Find the value of t t\,t when the cup of tea reaches 50∘C50^\circ\text{C}50∘C.

[3]
Markscheme

Exponentials and Logarithms Questions

  1. A Level
  2. /Maths
  3. /Exponentials and Logarithms

277 exam-style questions on Edexcel A Level Maths Exponentials and Logarithms, covering 14.1 Exponential Functions, 14.2 y = e^x, 14.3 Exponential Modelling, 14.4 Logarithms, 14.5 Laws of Logarithms, 14.6 Solving Equations using Logarithms, 14.7 Working with Natural Logarithms, and 14.8 Logarithms and Non-Linear Data. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank