Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter
    Offline

    0
    ReputationRep:
    A bacterial population N varies with time t (seconds) according to the general equation

    Nt = N0e^-λt Where N0 and λ are constants.

    i) Use your equation Nt= 83000e^-0.026t and plot a large graph with sufficient calculated values of N at suitable values of t so that you can read offthe decimal reduction time (values of t plotted may need to be higher than 100s depending on your value of λ).

    ii) Calculate the decimal reduction time from the data in your equation.

    iii) compare your answers in i) and ii) above.

    please help in how you would come about plotting the graph!
    Offline

    0
    ReputationRep:
    (Original post by geek-mode)
    A bacterial population N varies with time t (seconds) according to the general equation

    Nt = N0e^-λt Where N0 and λ are constants.

    i) Use your equation Nt= 83000e^-0.026t and plot a large graph with sufficient calculated values of N at suitable values of t so that you can read offthe decimal reduction time (values of t plotted may need to be higher than 100s depending on your value of λ).

    ii) Calculate the decimal reduction time from the data in your equation.

    iii) compare your answers in i) and ii) above.

    please help in how you would come about plotting the graph!
    Do you know what the graph of y=e^(-x) looks like? Do you know what the graphs of y= a f(x) and y=f(ax) look like relative to the graph of y=f(x)? That's all you need to be able to plot the graph they're asking for in the question - they're just after a sketch, not an accurate plot.
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: April 2, 2013
Poll
Are you going to a festival?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.