The 'line of best fit' is a line that goes roughly through the middle of all the scatter points on a graph. The closer ... meaning whether there is a positive, negative or no correlation.

A perfectly negative correlation means the relationship that exists between two variables is exactly opposite. In a line graph ... 1.0 indicates a perfectly positive correlation.

The gradient of a velocity-time graph at ... the constant positive acceleration graphs, the initial displacement is zero and the initial velocity is zero. For the constant negative acceleration ...