graphs!!

• co-ordinates with the same x-value produce a vertical line.
• co-ordinates with the same y-value create a horizontal line
• using a table of values, sometimes we only need to put down a few points and the rest is just continue, assuming the results
• gradient - the measure of how steep or shallow a line is. the bigger the gradient, the steeper the line
• y = mx + c
• the way we work out a gradient of any line is using the formula: gradient = change in y / change in x
• equations with the same gradient produce parallel lines, even if they start at different points
• y-intercept: the lines cross at the y-axis at the y-intercept. this number is at the end of our equation (example: y = 3x +4 - y-intercept
• to work out equations of straight lines with given information and no graph, we first find the equation of the line with the gradient aqnd passing through point
• a quadratic equation contains an x² term (and no higher powers)
• a distance time graph shows the relationship of how far something has travelled and how long it has taken to travel that distance
• scatter graph- a scatter graph compares two variables to analyse whether there is a relationship between them
• positive correlation - when the one variable increases, the other increases
• outlier - like a sort of anomaly that doesn't fit with the trend
• if the numbers are really random and do not follow a pattern, there is not correlation