k = 2

#postscript("../../WriteUp/Graphics/Chapter2/chap_2_sect_5_prob_7_plot.eps", onefile=FALSE, horizontal=FALSE)

ys = seq( -5, +5, length.out=100 )
fs = k*(1-ys)^2

plot( ys, fs, type='l', col='black', xlab='y', ylab='f(y)' )
abline(h=0, col='black', lty=1, lwd=2)
grid()

#dev.off()


if( FALSE ){ 
    ts = seq( 0, 10, length.out=100 )

    y0 = 3
    y0_3 = ( (y0-1)*k*ts - y0 ) / ( (y0-1)*k*ts - 1 ) # should diverge to +Inf

    y0 = 0.5
    y0_n5 = ( (y0-1)*k*ts - y0 ) / ( (y0-1)*k*ts - 1 ) # should converge to 1

    #postscript("../../WriteUp/Graphics/Chapter2/chap_2_sect_5_prob_7_plot_yt.eps", onefile=FALSE, horizontal=FALSE)

    plot( ts, y0_3, type='l', col='black' )
    lines( ts, y0_n5, type='l', col='red' )
    grid()

    #dev.off()
}