#====================
# Figure 9.5.R.
# Plots of sine and cosine functions.
#====================
th.lo=-4*pi
th.hi=4*pi
theta=th.lo+(th.hi-th.lo)*(0:1000)/1000  # Values of theta ranging
                                         #  from -4*pi to +4*pi.
y1=sin(theta)
y2=cos(theta)
plot(theta,y1,type="l",lty=1,ylim=c(-2,2),xlab="theta",ylab="sine and cosine")
points(theta,y2,type="l",lty=2)