# How can I access graph package for illustrating solutions to questions?

Aug 28, 2016

Click on the 'Graph' button in the toolbar, then enter the equation of function you wish to graph.

#### Explanation:

When answering a question, the toolbar above the edit window contains a 'Graph' button.

Clicking this button will bring up a window in which to enter the formula of the function to graph.

You can express the formula as a function of $x$, or write an equation in terms of $x$ and $y$.

If you want to graph more than one function at once express the formula as the product of terms equated to zero, i.e. in the form $\left(y - f \left(x\right)\right) \left(y - g \left(x\right)\right) = 0$, etc.

graph{((x+3)^100+(y-3)^100-2^100)((x-3)^100+(y-3)^100-2^100)(x^2+(y-3)^2-7)(y-3-sin(x)) = 0 [-9.96, 10.04, -2.48, 7.52]}

To limit the graph to a particular horizontal interval $\left[a , b\right]$, you can multiply by an expression of the form $\sqrt{\left(x - a\right) \left(b - x\right)}$.

For example, here I multiply by $\sqrt{9 - {x}^{2}}$ to limit the horizontal interval to $\left[- 3 , 3\right]$ ...

graph{sqrt(9-x^2)((x+3)^100+(y-3)^100-2^100)((x-3)^100+(y-3)^100-2^100)(x^2+(y-3)^2-7)(y-3-sin(x)) = 0 [-9.96, 10.04, -2.48, 7.52]}

To mark individual points you can use small circles, but they can easily disappear or be slightly misdrawn if you make them too small.

graph{((x-3)^2+(y-5)^2-0.023)((x+3)^100+(y-3)^100-2^100)((x-3)^100+(y-3)^100-2^100)(x^2+(y-3)^2-7)(y-3-sin(x)) = 0 [-9.96, 10.04, -2.48, 7.52]}

It is possible to get the graphing facility to draw triangles, squares and circles. I have not worked out how to do pentagons yet.

For example:

$\left({\left(\frac{\sqrt{3}}{2} \frac{x - 2}{1 - \frac{1}{\sqrt{3}} \left(y - 1\right)}\right)}^{100} + {\left(y - \frac{\sqrt{3}}{2} - 1\right)}^{100} - {\left(\frac{\sqrt{3}}{2}\right)}^{100}\right) \left({\left(x - 4.5\right)}^{100} + {\left(y - 2\right)}^{100} - {1}^{100}\right) \left({\left(x - 7\right)}^{2} + {\left(y - 2\right)}^{2} - {1}^{2}\right) = 0$

graph{((sqrt(3)/2(x-2)/(1-1/sqrt(3)(y-1)))^100+(y-sqrt(3)/2-1)^100-(sqrt(3)/2)^100)((x-4.5)^100+(y-2)^100-1^100)((x-7)^2+(y-2)^2-1^2) = 0 [-0.2, 9.8, -1.11, 3.89]}