Evaluate line segment C from P to Q

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Homework Statement


Evaluate ∫C F⋅dr along the line segment C from P to Q

F(x,y) = 8 i + 8 j ; P (-4,4) , Q (-4,5)

Homework Equations

The Attempt at a Solution


I believe I got most of the work done but I am have trouble finding the limits of the curve.

What I have done was create a vector v=PQ= <0,1>. I then made the parametric equations:

x = -4
y= 4 + t

I then derived x & y to get a dr(t) = dt j

F dot dr gives me 8dt... combining everything I get ∫C 8dt.

To find the limits of C I plugged Q into the parametric equations to give me values of t which were 0 & 1.

Attached is my work to clarify, not sure if correct.
 

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Your result is correct, but you do not need to integrate, as it is a constant force.
 
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There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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