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## hawkfalcon Group Title What is x in this equation? one year ago one year ago

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1. hawkfalcon Group Title

$\cos^2x +3cosx+2 = 0$

2. Mimi_x3 Group Title

u = cosx

3. hawkfalcon Group Title

Oh then its just a quadratic :O

4. hawkfalcon Group Title

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

5. Mimi_x3 Group Title

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

6. hawkfalcon Group Title

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

7. Mimi_x3 Group Title

np

8. hawkfalcon Group Title

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

9. Mimi_x3 Group Title

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.

10. hawkfalcon Group Title

Alright! Thank you so much:D