By Richard Tang
Mathematics / Algebra / Graphs

Many algebraic expressions can be interperated as graphs. Each expression would have a different graph. The shape of the graph can be found from the equation.

The graph made from a linear equation would give a stright line graph. Linear equations are written in the form y = mx + c. From that you can see that the m represents the gradient of the graph and that c shows the point where the graph crosses the y-axis. Here are some examples:

y = x y = 2 x = - 6 y = 2 - 2 x

These graphs are n or u shaped curves, or parabolas. They all have an axis of symmetry. The equation for these graphs are in the form y = ax2 + bx + c. This means the highest power would be x2. Below are some examples:

y = x2 y = - x2 y = x2 - 8 y = ( x + 6 )2

Cubic graphs should have upto two turning points. They come in many forms. They do not have to be symmetrical. The equation for these graphs are in the form y = ax3 + cx2 + dx + e. This means the highest power would be x3. Below are some examples:

y = x3 y = - x3 y = x3 - 8 x

These graphs are all hyperbolas. This means they consist of two separate lines which are opposite each other as though they were a reflection of each other. The equations for this type of graph come in the form y = a / x. Below are some examples:

y = 1 / x y = 10 / x - 2

Mathematics / Algebra / Graphs