(adsbygoogle = window.adsbygoogle || []).push({}); Find the unit vector that makes an angle θ=-3∏/4 with the positive x-axis

I know to find a unit vector you divide the given vector by its magnitude, so I guess my problem is finding any vector that makes that angle with the positive x axis. I figured if that angle was the slope of a line, then when x=1, y=-3∏/4. So I divided the vector <1,-3∏/4> by its magnitude and got the wrong answer. Could someone point me in the right direction?

Thanks in advance.

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# Finding a unit vector.

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