## Harder Curve Sketching; 3u Math

We just started this topic and i don't fully grasp the concepts.
After determining asymptopes (do therehave to be vertical/horizontal asymptopes? i.e where x cannot = 0 etc?)
and finding the derivitives of the eq'n, my teacher showed us how to sketch them:

1. Dot a line whereever the horiz/vert asymptope is. This is a 'jump', or where the curve cannot cross.

2. Plot points of max/min/inflexion

3. Break down the line formula (e.g y = x-1/x^2 becomes three lines; y=x-1, y=x, y=x)

4. When these lines are in a positive area (above the xaxis) place a + on them. Shade the area where they are + or -. (I.e three lines are +/+/+ sketch in the positive area, if its -/+/+ sketch neg, -/-/- sketch neg etc)

This is where i get stuck. What is the sketching for? Is it to know where the curve can be??