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Reply 1
Avatar for mqb2766
mqb2766
21
What are you stuck with?
Reply 2
Avatar for hexanimal
hexanimal
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6
I don’t really understand how to eliminate the theta from x=7cosx+2cos2x.
Reply 3
Avatar for mqb2766
mqb2766
21
Original post by hexanimal
I don’t really understand how to eliminate the theta from x=7cosx+2cos2x.

The question does not ask you to do that? Why is it ncessary?
Reply 4
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hexanimal
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Original post by mqb2766
The question does not ask you to do that? Why is it ncessary?


I thought that was what you were meant to do, and I didn’t know how to start.
Reply 5
Avatar for mqb2766
mqb2766
21
Original post by hexanimal
I thought that was what you were meant to do, and I didn’t know how to start.

Sometimes it is, but the whole point of a parameterized curve is that its expressed in terms of a single parameter, theta.

a) is finding the max y value.
y = 2 + sin(theta)
So ...
Reply 6
Avatar for hexanimal
hexanimal
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6
Original post by mqb2766
Sometimes it is, but the whole point of a parameterized curve is that its expressed in terms of a single parameter, theta.

a) is finding the max y value.
y = 2 + sin(theta)
So ...


For y =2 + sin(theta) I got y-2 = sin(theta)
For the 2nd equation I was thinking of using cos2(theta)=1-2(sin)^2(theta)
Original post by hexanimal
For y =2 + sin(theta) I got y-2 = sin(theta)
For the 2nd equation I was thinking of using cos2(theta)=1-2(sin)^2(theta)

for part a) just think how the value of y changes as the sin function takes various values.

for part b) you are trying to make x = 0
Reply 8
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mqb2766
21
you're posting equation transformations without explaining why/how they help. How is y maximized for a)
Reply 9
Avatar for hexanimal
hexanimal
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6
Thx for the help, I guess I was making this a bit more complicated than it need to be

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