Exercise 4: R trigonometric functions
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Find a function FUN that leads to the following output:
curve(FUN, from = -10, to = 10, col = "red", ylim = c(-2, 2)) curve(sin, add = TRUE) grid()
Hint: aim to keep the answer simple. The main logic of the function can often be summarized in a single line of R code.
Answer 1: click to reveal
We can write the function as follows:
FUN <- function(x) {
return(sin(x + pi / 2))
}
We then get:
curve(FUN, from = -10, to = 10, col = "red", ylim = c(-2, 2)) curve(sin, add = TRUE) grid()
Answer 2: click to reveal
We can use various trigonometric identities to derive more solutions to this puzzle. For example:
sin(x + pi/2) = cos(x)
FUN can then be defined as:
FUN <- function(x) {
return(cos(x))
}
We can confirm that this function solves the puzzle:
curve(FUN, from = -10, to = 10, col = "red", ylim = c(-2, 2)) curve(sin, add = TRUE) grid()
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