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# Core 4 parametric equations help watch

1. So I'm stuck on this question for Core 4. I need to find the cartesian equation of the parametric equations:

X = 3cos^2(t)

Y= sin(2t)

In the form Y^2= f(X)

Obviously I don't want people to just tell me the answer. If it wasn't for the 2t in the equation for Y it would be straightforward but I just cannot see where to start.

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2. Use the double angle formula.
sin 2t = 2 sin(t) cos(t)
3. (Original post by TheMightyAugur)
So I'm stuck on this question for Core 4. I need to find the cartesian equation of the parametric equations:

X = 3cos^2(t)

Y= sin(2t)

In the form Y^2= f(X)

Obviously I don't want people to just tell me the answer. If it wasn't for the 2t in the equation for Y it would be straightforward but I just cannot see where to start.

Posted from TSR Mobile
As said above use the double angle formula for sin(2x) and then try using sin^2(x) + cos^2(x) = 1 to get Y^2 in terms of cos^2(x) and hopefully you'll be able to figure out the rest from there

Posted from TSR Mobile

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