Hi, I have a question on double angle formulae: Eliminate theta from the equation x = 2 sec theta, y = cos 2 theta The answer is x^2y = 8 - x^2 Thank you!
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Originally Posted by sakuraxkisu Hi, I have a question on double angle formulae: Eliminate theta from the equation x = 2 sec theta, y = cos 2 theta The answer is x^2y = 8 - x^2 $\displaystyle x = 2 \sec{\theta} \implies \cos{\theta} = \frac{2}{x}$ $\displaystyle y = \cos(2\theta) = 2\cos^2{\theta} - 1$ proceed ...
Thank you so much! I feel like a bit of an idiot as that was so simple haha
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