Show that the function defined by `f(x) = | cos x |`is a continuous function.

Explanation

Let `g(x)=cos x` and `h(x)=|x|` be two functions defined on R.
Then `" (hog) (x) = h (g (x))"`
`" "=h(cosx)=|cosx|`
`" "=f(x)," for all " x in R`
g(x) = cos x, being a cosine function, is continuous on R.
h(x) = cos x, being a modulus function, is continuous on R.
`therefore" "f(x)=(hog)(x)`, being a composition of two continuous functions, is continuous on R.
Hence, f(x) = |cos x | is continuous function.