The tangent can be determined with a collection of mathematical formulas but is most commonly determined by dividing the sine function by the cosine function.

National 5 Working with the graphs of trigonometric functions Phase angle Trigonometric graphs can be sketched when you know the amplitude, period, phase and maximum and minimum turning points.

Excel's intercept function takes the data points that define a line on a graph and calculates the y value for the point on the graph where x is equal to zero.