Question: I am building a web application and trying to link a stylesheet to my app. Here is my code

```
<html>
    <head>
        <title>Bubble</title>
    </head>
    <link rel="stylesheet" href="./public/main.css">   
<body>

```

The app is located in the direct DrDenver/blog. The full style sheet is located in DrDenver/blog/public.

Answer: 
I have not done the math, but instead wrote the tests. It seems you got a sign error when assigning m and c.

Also, writing the tests really helps, and Julia makes it simple :)

```
function GradientDescent(x, y)
   m=0.0
   c=0.0
   for i=1:10000
      for k=1:length(x)                       
        Yp = m*x[k] + c   
        E = y[k]-Yp
        dm = 2*E*(-x[k])
        dc = 2*E*(-1)

        m = m - (dm * 0.001)
        c = c - (dc * 0.001)
       end
   end
   return m,c
end

using Base.Test

@testset "gradient descent" begin
    @testset "slope $slope" for slope in [0, 1, 2]
        @testset "intercept for $intercept" for intercept in [0, 1, 2]
            x = 1:20
            y = broadcast(x -> slope * x + intercept, x)

            computed_slope, computed_intercept = GradientDescent(x, y)
            @test slope ≈ computed_slope atol=1e-8
            @test intercept ≈ computed_intercept atol=1e-8
        end
    end
end

```
I can't get your exact numbers, but this is close. Perhaps it helps?

```
                                        # 141 ?  
datax = [1,2,3,4,5,6,7,8,9,10,11,12,13,141,5,16,17,18,19,20]
datay = [2,3,4,5,6,7,8,9,10,11,12,13,141,5,16,17,18,19,20,21]

function gradientdescent() 
    m = 0
    b = 0
    learning_rate = 0.00001
    for n in 1:10000
        for i in 1:length(datay)
            x = datax[i]
            y = datay[i]
            guess = m * x + b
            error = y - guess
            dm = 2error * x
            dc = 2error
            m += dm * learning_rate
            b += dc * learning_rate
        end
    end 
    return m, b
end

gradientdescent()

(-0.04, 17.35)

```

It seems that adjusting the learning rate is critical...