### A good answer might be:

The problem is that `sin(x)`

has values from -1.0 up to 1.0.
When these are changed to `int`

type
in the statement

int startY = (int)Math.sin( x );

they will almost always
be zero.

# Adjusting Values

To use the `drawLine()`

method, the endpoints of
the line need to be positive integers.
But what we want to graph consists of negative and positive
numbers smaller than one!

To deal with this problem you need to scale the computed values
into graphics coordinates.
Say that the applet is 600 pixels wide,
and that this is supposed to represent the range of 0.0 to 2*PI.
So we have:

actual x value | integer X to fit applet width |

0.0 | 0 |

2*PI | 599 |

The floating point number `x`

can be changed into the
correct integer `X`

by using a linear equation:

X = x * 599/(2*PI)

This may look awful, but it is just algebra.