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# fp1 complex numbers

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Why bother with a post grad? Are they even worth it? Have your say! 26-10-2016
1. (Original post by kinderbar)
it just said in the question that p>0 so i know that q=-2
I forgot about that. But even without that information you should still be able to decide.
2. (Original post by B_9710)
I forgot about that. But even without that information you should still be able to decide.
so the other angle with the positive x-axis would be something like 3pi/4 ?
3. (Original post by kinderbar)
so the other angle with the positive x-axis would be something like 3pi/4 ?
That's right.
4. (Original post by B_9710)
That's right.
So this Newton-Raphson numerical method in solving an equation where f(x)=0 where can i not use it?
5. (Original post by kinderbar)
So this Newton-Raphson numerical method in solving an equation where f(x)=0 where can i not use it?
What do you mean, where you can't use it?
You can use it on any equation if you've got an interval or know an approximation.
6. (Original post by Chittesh14)
What do you mean, where you can't use it?
You can use it on any equation if you've got an interval or know an approximation.
That;'s what i was looking for. thanks !
7. (Original post by kinderbar)
That;'s what i was looking for. thanks !
No problem .
8. (Original post by kinderbar)
So this Newton-Raphson numerical method in solving an equation where f(x)=0 where can i not use it?
The method can fail sometimes. See 'failure analysis' on Wikipedia https://en.m.wikipedia.org/wiki/Newton%27s_method
9. (Original post by B_9710)
The method can fail sometimes. See 'failure analysis' on Wikipedia https://en.m.wikipedia.org/wiki/Newton%27s_method
Every method fails . All of the 3 numerical methods are unreliable but some are more than others.
I'm just happy that they're worth so many marks in the exam apparently and the questions aren't as hard as they are in the textbook, or I should say long lol.

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10. (Original post by B_9710)
The method can fail sometimes. See 'failure analysis' on Wikipedia https://en.m.wikipedia.org/wiki/Newton%27s_method
Should part (b) equal to 6root17

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11. (Original post by Chittesh14)
Should part (b) equal to 6root17
Spoiler:
Show

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Yes it does.
Spoiler:
Show
12. (Original post by MartyO)
Yes it does.
Spoiler:
Show
Thanks, I knew it. The answers said 6root7 lol.

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13. (Original post by B_9710)
The method can fail sometimes. See 'failure analysis' on Wikipedia https://en.m.wikipedia.org/wiki/Newton%27s_method
(Original post by MartyO)
Ye

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14. (Original post by MartyO)
Yes it does.
Spoiler:
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15. a) The gradient of the normal is equal to the opposite of the inverse of the gradient of the tangent.

You have to find the derivative of the hyperbola to find the equation of the normal at P, with the vertex formula of a line (at ):

Full demo:
Spoiler:
Show
b) We recall the formula for the normal at P, and have it intersect with . We solve for to find the coordinates of G.
Full demo:
Spoiler:
Show
From there, it's a matter of finding the distance between P and G and square it.

Full demo:
Attached Images

16. (Original post by MartyO)
a) The gradient of the normal is equal to the opposite of the inverse of the gradient of the tangent.

You have to find the derivative of the hyperbola to find the equation of the normal at P, with the vertex formula of a line (at ):

Full demo:
Spoiler:
Show
b) We recall the formula for the normal at P, and have it intersect with . We solve for to find the coordinates of G.
Full demo:
Spoiler:
Show
From there, it's a matter of finding the distance between P and G and square it.

Full demo:
I've done part a already and got it correct. It's part b I need help on. Can you reattach the images for part b, they don't work.

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17. (Original post by Chittesh14)
I've done part a already and got it correct. It's part b I need help on. Can you reattach the images for part b, they don't work.

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Here:
Spoiler:
Show
18. http://www.examsolutions.net/maths-r.../example-1.php
In this video he uses implicit diff which i don't know how to do so i just square rooted both sides and used c1 diff from there to get tangents and normals but the implicit diff method gives the tangent and normal on the point (9,-12) so do i need to include all the tangents and normals?
19. (Original post by MartyO)
Here:
Spoiler:
Show
Thanks man, I love you.
That question was so fkin hard.

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20. (Original post by MartyO)
Here:
Spoiler:
Show
Can u help me on this too

Part b

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