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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!
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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

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