Functions

Use R to graph a function with the plot command.

#create a simple x range
x <- seq(-5,5,0.1)

#define the function y=x^2
y <- x^2

#plot using base R
plot(x,y, type="l", col="green", lwd=2,
     main="Graph of y=x^2",
     xlab="x", ylab="y")

We say that \(f:X\ to\ Y\) is a function if for every \(x \in X\) there exists a UNIQUE \(y \in Y\) such that \(f(x)=y\).

f <- function(x) x^3
curve(f,from = -4, to= 4, n=400, 
      xlab = "x", ylab = "y", lwd=2, col="pink",
      main="Vertical Line Test: y=x^2 (Function)")

Define the function and graph it.

Add a new chunk by clicking the Insert Chunk button on the toolbar or by pressing Ctrl+Alt+I.

When you save the notebook, an HTML file containing the code and output will be saved alongside it (click the Preview button or press Ctrl+Shift+K to preview the HTML file).

The preview shows you a rendered HTML copy of the contents of the editor. Consequently, unlike Knit, Preview does not run any R code chunks. Instead, the output of the chunk when it was last run in the editor is displayed.