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I am stuck on how to do this problem, I'm not even sure if my solutions for questions 1 and 2 are even correct. enter image description here

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    Please do not use pictures for critical portions of your post. Pictures cannot be searched and are inaccessible to those using screen readers. Ref:https://meta.stackexchange.com/q/116050/259305 – 2017-03-10

1 Answers 1

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1 and 2 are correct. Just do the same for 3. $(-\vec{i}-\vec{j})$ means that you need to go along the diagona from the upper right corner towards the lower left corner

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    So $(-\vec{i}$ means along the x axis and $-\vec{j})$ is the y axis correct? What is an easier way to read $(-\vec{i}-\vec{j})$ so that on the top of my head I automatically know it should be from the upper right corner towards the lower left corner? Also, could you post how you would write out #3 just like how I did? So I can understand it better. – 2017-02-28
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    $+\vec{i}$ is along the x axis to the right, $-\vec{i}$ is to the left. Same for $+\vec{j}$ is up, $-\vec{j}$ is down. So $-\vec{i} -vec{j}$ is down and left – 2017-02-28
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    Does the denominator affect the direction at all? Also, for #4, what does the "-2" do to $\vec{j})$? – 2017-02-28
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    only the sign is important. The magnitude is there just for the size of the derivative, it will not change the sign – 2017-02-28