hawkfalcon
What is x in this equation?



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hawkfalcon
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\[\cos^2x +3cosx+2 = 0\]

Mimi_x3
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u = cosx

hawkfalcon
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Oh then its just a quadratic :O

hawkfalcon
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:P What happens to the cos though? Do it after?

Mimi_x3
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u^2 + 3u + 2 = 0
solve for u then later sub it back in
btw is it only me that latex is not working?

hawkfalcon
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Okay, thank you. I think its just you:O

Mimi_x3
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np

hawkfalcon
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I can't believe I didn't see it was just a simple quadratic *.*

Mimi_x3
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well using a substitution is easier; at times when you see like the x squared; there is a high chance that its a quadratic. so use a substitution.

hawkfalcon
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Alright! Thank you so much:D