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Polar graphing

Question asks me to draw r = a(1 - cost), (t = theta).

I drew a table of values as completed the question but now when I look over my notes a dimple is only meant to occur when q ≤ p < 2q when r = a(p +qcost).

In our example p = 1, q = -1, 2q = -2 so p > 2q but there is still a dimple???
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TenOfThem
18
Original post by miketree
Question asks me to draw r = a(1 - cost), (t = theta).

I drew a table of values as completed the question but now when I look over my notes a dimple is only meant to occur when q ≤ p < 2q when r = a(p +qcost).

In our example p = 1, q = -1, 2q = -2 so p > 2q but there is still a dimple???


by dimple do you mean the bit inside

if so, you should not have one for this question
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miketree
OP
Original post by TenOfThem
by dimple do you mean the bit inside

if so, you should not have one for this question


Untitled.png

A dimple like the above, this is the general shape but it's not to scale.
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TenOfThem
18
Original post by miketree
Untitled.png

A dimple like the above, this is the general shape but it's not to scale.


Oh, yes you should have that

It is this bit that only appears with, for example 1+2Cosθ\theta

http://www.wolframalpha.com/input/?i=r%3D1%2B2cos%28theta%29
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miketree
OP
Original post by TenOfThem
...


Ok so from what I understand, p=∣p∣p = |p| and q=∣q∣q = |q|, i.e. 'dimple' when ∣q∣≤∣p∣<∣2q∣|q| \leq |p| < |2q|.

Is that all ok or no?

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