Monotonicity of Functions

General Mathematics — Second Secondary

Finding monotonicity from a graph and a table

From a graph, follow the curve from left to right and write down the interval where it rises (increasing) and the interval where it falls (decreasing).
The turning point, a peak or a valley, separates the two intervals.
From a table of values, compare each output with the next one.
If f(x) keeps increasing as x increases, the function is increasing on that part of the table.
If the outputs decrease, the function is decreasing there.

x	−2	−1	0	1	2	3
f(x)	4	1	0	1	4	9

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