I apparently forget too much algebra. I'm trying to have one scale going from 4 to 9, with a value of 300 starting at four that decreases by 2/3 every point to 9. On my TI-83 calculator, I have set the window at:
Xmin= 4
Xmax= 9
Xscl=1
Ymin= 0
Ymax=350
Yscl= 10
Xres= 1
I made the function: y= 2/3x + 300
I graphed that, and a horizontal line formed at y=300. I want to be able to trace values of >300 part for every 1/10th of a point on the first scale, 4-9. What am I doing wrong?