You are Here: Home >< Maths

C3 Solomon A help!

Announcements Posted on
Why bother with a post grad? Are they even worth it? Have your say! 26-10-2016
1. 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. (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. (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

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

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. (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. (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

It is an exact value.
7. (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

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

Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
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
1. Oops, you need to agree to our Ts&Cs to register

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.

This forum is supported by:
Today on TSR

Who is getting a uni offer this half term?

Find out which unis are hot off the mark here

Brexit: Why you should study law

Poll
Useful resources
Study resources

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

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