Results are out! Find what you need...fast. Get quick advice or join the chat
Hey! Sign in to get help with your study questionsNew here? Join for free to post

C3 Solomon A help!

Announcements Posted on
Fancy winning £500? Join the Summer Bucket List Challenge and beat the holiday boredom! 06-07-2015
Waiting on IB results? Our IB results hub explains everything you need to know 01-06-2015
  1. Offline

    ReputationRep:
    Hey guys I'm just going through the uploaded question. I've managed part A, but on part B I'm unsure of what the question is asking. So far I have differentiated the function y and tried to work out the gradient when x has a value of pi/4 but I'm getting a weird decimal answer I think the question is asking me to work out the equation of the tangent to the curve and then sub in the values of when x=0 to work out the y intercept? Is this correct, and if not what am I doing wrong Thanks!
    Attached Images
     
  2. Offline

    ReputationRep:
    (Original post by Bugsy)
    Hey guys I'm just going through the uploaded question. I've managed part A, but on part B I'm unsure of what the question is asking. So far I have differentiated the function y and tried to work out the gradient when x has a value of pi/4 but I'm getting a weird decimal answer I think the question is asking me to work out the equation of the tangent to the curve and then sub in the values of when x=0 to work out the y intercept? Is this correct, and if not what am I doing wrong Thanks!
    Yes that is what it is asking, what have you got for the equation of the tangent?
  3. Offline

    ReputationRep:
    (Original post by Bugsy)
    Hey guys I'm just going through the uploaded question. I've managed part A, but on part B I'm unsure of what the question is asking. So far I have differentiated the function y and tried to work out the gradient when x has a value of pi/4 but I'm getting a weird decimal answer I think the question is asking me to work out the equation of the tangent to the curve and then sub in the values of when x=0 to work out the y intercept? Is this correct, and if not what am I doing wrong Thanks!
    Find the equation of the tangent at  x = \dfrac{\pi}4

    Then sub in x=0 to get the answer.
  4. Offline

    ReputationRep:
    (Original post by TheJ0ker)
    Yes that is what it is asking, what have you got for the equation of the tangent?
    I haven't managed to get an equation for the tangent yet, because I can't work out a value for m I tried to sub in pi/4 into my dy/dx but like I said I get a long decimal which I don't think is correct.. Once I get a M value I can use the y-y1=m(x-x1) to find the equation for the tangent..

    (Original post by raheem94)
    Find the equation of the tangent at  x = \dfrac{\pi}4

    Then sub in x=0 to get the answer.
    Yeah this is what I'm having problems with.. For my dy/dx I got 2x.Sec^2 x + 2tanx
  5. Offline

    ReputationRep:
    (Original post by Bugsy)
    I haven't managed to get an equation for the tangent yet, because I can't work out a value for m I tried to sub in pi/4 into my dy/dx but like I said I get a long decimal which I don't think is correct.. Once I get a M value I can use the y-y1=m(x-x1) to find the equation for the tangent..



    Yeah this is what I'm having problems with.. For my dy/dx I got 2x.Sec^2 x + 2tanx
    Don't just plug the numbers into a calculator then. If you do it using your grey matter you will get a simple gradient involving an integer and pi.
  6. Offline

    ReputationRep:
    (Original post by Bugsy)
    Yeah this is what I'm having problems with.. For my dy/dx I got 2x.Sec^2 x + 2tanx
    Sub in  x = \dfrac{\pi}4

     \displaystyle \frac{dy}{dx} = 2 \times \frac{\pi}4 \times sec^2\frac{\pi}{4} + 2 tan \frac{\pi}4 = \frac{\pi}2 \times 2 + 2 = 2 + \pi

    It is an exact value.
  7. Offline

    ReputationRep:
    (Original post by TheJ0ker)
    Don't just plug the numbers into a calculator then. If you do it using your grey matter you will get a simple gradient involving an integer and pi.
    (Original post by raheem94)
    Sub in  x = \dfrac{\pi}4

     \displaystyle \frac{dy}{dx} = 2 \times \frac{\pi}4 \times sec^2\frac{\pi}{4} + 2 tan \frac{\pi}4 = \frac{\pi}2 \times 2 + 2 = 2 + \pi

    It is an exact value.
    Ah okay, great I get the answer now! Sorry for being so silly, I should have tried to do it without a calculator to get an exact value.. Thanks for your help

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide to join now Processing…

Updated: June 3, 2012
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

New on TSR

IB results chat

Good luck everyone - loads of support here

Study resources
x

Think you'll be in clearing or adjustment?

Hear direct from unis that want to talk to you

Get email alerts for university course places that match your subjects and grades. Just let us know what you're studying.

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