W 4/15/9

Due tomorrow:
* group project from class (1 asmt per group)
* RA §5.4a
* WAMAP §5.3b

Due on Fri (@ test):
* two proofs using hyperbolic trig functions:
1. cosh^2(x) - sinh^2(x) = 1
2. d/dx tanh(x) = sech^2(x)

Mathematica bonus (due Fri @ test):
* take the following code and re-code it so that the area under the curve is red, and the area above is blue
f[x_] := Abs[x - 2] - Abs[x - 8] + 2;
Plot[f[x], {x, -5, 10}, Filling -> Axis, PlotStyle -> Thick, PlotRange -> {-5, 25}]