If cos⁡ x=−45, and 180° < x < 270°, what is tan⁡(2x)?

Step-by-step explanation:

Here we have , cos x = -4/5 ( corrected as given -45 which is not possible ) ,

180° < x < 270° i.e. in third quadrant  . We need to find tan⁡(2x) . Let's find out:

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⇒ , since in third quadrant . remains same .

Now ,

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Therefore, .

the first one is x^2+2x+2

the second one is x^2+4

the last one is x^2-4x+8