# List of functions used for tangent/normal 2D.
# An item in this list will be picked randomly at each exercise.
# Structure of item: multi-line.
# line 1 is function description.
# line 2 is derivative.
# line 3 is proportionality
# The rest is values for parameters c1, c2, etc.

:c1*t^c4+c2*t+c3,c6*t^c5+c7*t+c8
 c1*c4*t^(c4-1)+c2,c6*c5*t^(c5-1)+c7
 1.5
 -0.9,-0.8,-0.7,-0.6,-0.5,-0.4,-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9
 -1.5,-1.4,-1.3,-1.2,-1.1,-0.9,-0.8,-0.7,-0.6,-0.5,-0.4,-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.1,1.2,1.3,1.4,1.5
 -1.5,-1.4,-1.3,-1.2,-1.1,-0.9,-0.8,-0.7,-0.6,-0.5,-0.4,-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.1,1.2,1.3,1.4,1.5
 2,3
 2,3
 -0.9,-0.8,-0.7,-0.6,-0.5,-0.4,-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9
 -1.5,-1.4,-1.3,-1.2,-1.1,-0.9,-0.8,-0.7,-0.6,-0.5,-0.4,-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.1,1.2,1.3,1.4,1.5
 -1.5,-1.4,-1.3,-1.2,-1.1,-0.9,-0.8,-0.7,-0.6,-0.5,-0.4,-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.1,1.2,1.3,1.4,1.5

