# 1. feladat: regresszió+ábrázolás

x <- 4*pi*runif(100)
x <- sort(x)
y <- 2*sin(x+pi/6) + 1 + rnorm(100)

reg1 <- lm(y ~ sin(x))
reg2 <- lm(y ~ sin(x) + cos(x))

plot(x,y,pch=2,col="blue")
lines(x,reg1$fitted,lty=2,col="green")
lines(x,reg2$fitted,col="red")

legend("bottomleft",legend=c("Adatok","y ~ sin(x)","y ~ sin(x) + cos(x)"),
	pch=c(2,NA,NA),lty=c(NA,2,1),col=c("blue","green","red"))