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# C2 Trig Watch

1. Im currently on part b.
What does the question mean by saying q < 180?
Also, I plugged in the y/x values into the equations getting:

for A(100, 0) and
for B(220, 0).

and

When I try solving I get something like p = 0, which is rubbish. What am I doing incorrectly?
Thanks

PS just for the reference for part a, is the best approach to change the interval from 0 < x < 360 to 0 < 2x < 360, find the solutions, add 30 then divide by 2?
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2. (Original post by UKBrah)
Im currently on part b.
What does the question mean by saying q < 180?
Also, I plugged in the y/x values into the equations getting:

for A(100, 0) and
for B(220, 0).

and

When I try solving I get something like p = 0, which is rubbish. What am I doing incorrectly?
Thanks

PS just for the reference for part a, is the best approach to change the interval from 0 < x < 360 to 0 < 2x < 360, find the solutions, add 30 then divide by 2?
Well, A is your "primary" solution, so B must be a secondary solution.
3. Didnt clock that mate, sorry
4. (Original post by UKBrah)
Didnt clock that mate, sorry
If I have

AND

make sense?
5. (Original post by Indeterminate)
If I have

AND

make sense?
So x = 90, 270?..

How does that exactly help with my sim equations?
6. P must be 0 you can see that this must be true by just looking at the simultaneous equations brah

7. You can work out the period of the function from this, normally roots of a cosine function would be apart, here however they are only apart. So:

Now, the q is easily determined by noticing it's just going to translate the normal cosine function left/right (parallel to the x-axis) so work out where the roots would normally lie with the function , and you can work out the q from noting the coordinates of A, B and C.
8. (Original post by Noble.)

You can work out the period of the function from this, normally roots of a cosine function would be apart, here however they are only apart. So:

Now, the q is easily determined by noticing it's just going to translate the normal cosine function left/right (parallel to the x-axis) so work out the roots would normally lie with the function , and you can work out the q from noting the coordinates of A, B and C.
+1.

That didn't appeal to me at first
9. (Original post by raiden95)
P must be 0 you can see that this must be true by just looking at the simultaneous equations brah
p does not equal 0, it wouldn't be a cosine function if p = 0.
10. (Original post by Noble.)
p does not equal 0, it wouldn't be a cosine function if p = 0.
Oh I was looking at the simultaneous equation
11. (Original post by raiden95)
Oh I was looking at the simultaneous equation
Well, if p is zero then y = cos(-q) and since q is a constant y is just a straight line.

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