We have a function to find the gradient of `b`

at every point. To find the `m`

gradient, or the way the loss changes as the slope of our line changes, we can use this formula:

`$\frac{2}{N}\sum_{i=1}^{N}-x_i(y_i-(mx_i+b))$`

Once more:

`N`

is the number of points you have in your dataset`m`

is the current gradient guess`b`

is the current intercept guess

To find the `m`

gradient:

- we find the sum of
`x_value * (y_value - (m*x_value + b))`

for all the`y_value`

s and`x_value`

s we have - and then we multiply the sum by a factor of
`-2/N`

.`N`

is the number of points we have.

Once we have a way to calculate both the `m`

gradient and the `b`

gradient, we’ll be able to follow both of those gradients downwards to the point of lowest loss for both the `m`

value and the `b`

value. Then, we’ll have the best `m`

and the best `b`

to fit our data!

### Instructions

**1.**

Define a function called `get_gradient_at_m()`

that takes in a set of x values, `x`

, a set of y values, `y`

, a slope `m`

, and an intercept value `b`

.

For now, have it return `m`

.

**2.**

In this function, we want to go through all of the `x`

values and all of the `y`

values and compute `x*(y - (m*x+b))`

for each of them.

Create a variable called `diff`

that has the sum of all of these values, and return it from the function.

**3.**

Define a variable called `m_gradient`

and set it equal to the `-2/N`

multiplied by `diff`

.

Instead of returning `diff`

, return `m_gradient`

.

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