Question 30295
{{{ x^2+6x-2=0 }}}


To plot...pick values of x... your choice of values. I shall pick, -3, -2, -1, 0, 1, 2, 3.


For each of these, put it into {{{ y = x^2+6x-2 }}} to find what y is.


You will end up with 7 sets of x and y values. Plot these.


The question is asking you, where does the curve have y=0.. ie where does it cross the x-axis. That is all.


So, read off the value(s) of x where the curve crosses. If it crosses between integer values of x, say somewhere between x=2 and x=3, then they want you to write: 


The solution lies between x=2 and x=3.


This is because your graph will not be accurate enough to quote the precise answer, so you reading the value from your graph as x=2.3, for example, is a waste of time.


Oh yes, if you chose x-values and when you plot the graph you missed the point(s) that cross the x-axis, then tough... pick some more x-values and plot those too.


Basically this will teach you three things hopefully:
1. What an equation physically looks like
2. What "solving" physically means to an equation.
3. Graphs are a pain to plot and are not accurate anyway.


jon.