i want to understand the below more deeply : When we use Newton's method, we're essentially using the tangent line at our current guess (x_0) to approximate the function (f(x)). The x-intercept of this tangent line gives us our next guess (x_1). Because the tangent line is a good approximation to the function near (x_0), the x-intercept of the tangent line is typically a better approximation to the root than (x_0) was