Trouble with the Curve

Question

Say I have a square or a polygon. I want to transform one of the sides from straight to a smooth curve. Is there a way to do this?
I have the pen tool and I'm tracing an object. I want to create one curved side then continue on with straight edges. However the tool insists on creating 2 or 3 curves at a time.
Is there a way to create a single isolated or part of a shape curve thats adjustable with both endpoints. It seems that curves I create often are missing adjustment levers at one of their endpoints making it harder to get the shape I want.

Answer 1

Say I have a square or a polygon. I want to transform one of the sides from straight to a smooth curve. Is there a way to do this?
ALWAYS state what version of the program you are using. Assuming CS3 or later:
(View>Snap to Point on)
1. White pointer (the so-called Direct Selection Tool): Select the Anchor Point(s) of interest.
2. Control Panel (that strip along the top of the window): Click the Convert to Smooth button. The Anchor is changed to Smooth; both Direction Handles auto-extend.
3. White pointer: Drag the unwanted handle back into the Anchor.
or...
3. Convert Tool: Click the unwanted Handle.
I have the pen tool and I'm tracing an object. I want to create one curved side then continue on with straight edges. However the tool insists on creating 2 or 3 curves at a time.
1. Pen Tool: Click. (Places a Corner Point.)
2. Move the cursor. ClickDrag. (Places a Smooth Point, curved segment results.)
3. Click the Anchor you just placed. (Retracts the outgoing Handle.)
4. Move the cursor. Click (Places a Corner Point, straight segment results.)
Is there a way to create a single isolated or part of a shape curve thats adjustable with both endpoints. It seems that curves I create often are missing adjustment levers at one of their endpoints making it harder to get the shape I want.
1. Pen Tool: Click (Places a Corner Anchor Point.)
2. Move the cursor. Mousedown and drag. (Places a Smooth Anchor Point, curved segment results.)
3. Press and hold Alt. Continue to drag. (Outgoing Handle under the cursor moves independently of the incomming Handle.)
4. Mouseup. Move the cursor. Click or ClickDrag to set the next Anchor.
There are other ways to do some of the above, by pressing shortcut keys to switch to other tools. For example, while drawing with the Pen, you can press Alt to momentarily invoke the Convert Anchor Point Tool and drag a pre-existing SmoothPoint Handle, and move it independently of its opposite Handle (thereby converting the Smooth Anchor Point to a Corner Anchor Point).
One of Illustrator's weaknesses in this (aside from its overall comparitive tedium) is its inability to drag just one retracted handle out of a retracted Corner point to bend an existing straight segment.
There are 3 different types of anchor points - straight, smooth (two direction handles working in alignment) and cusp (two direction handles working independantly).
No.
Illustrator's interface defines two types of Anchor Points: Corner or Smooth. What you are calling a "Cusp" is just a CornerPoint with one or both of its Handles extended. "Cusp" (as a kind of Bezier control point) is a term germane to Corel Draw, not Illustrator.
Illustrator: Corner Point, Smooth Point
Draw: Cusp Node, Smooth Node, Symmetrical Node (Illustrator does not provide the symmetrical behavior.)
FreeHand: Corner Point, Curve Point, Connector Point (Illustrator does not provide the connector behavior.)
JET