Int 3 for Programmers

Composition and inverses by hand

Int 3 for Programmers

Composition and inverses by hand

Medium0 of 10 parts

Ten questions on running functions one after another and on running them backwards. Type sqrt(x) for a square root, and give rules in terms of xx.

For every inverse you find, check it in your head by sending one number through and back before typing the answer.

1

With f(x)=2x+3f(x) = 2x + 3 and g(x)=x2g(x) = x^2, find (f∘g)(2)(f \circ g)(2).

2

With the same two functions, find (g∘f)(2)(g \circ f)(2).

3

With f(x)=2x+3f(x) = 2x + 3 and g(x)=x2g(x) = x^2, write f(g(x))f(g(x)) in terms of xx.

in terms of x

4

With the same two functions, write g(f(x))g(f(x)) in terms of xx.

in terms of x

5

Find the inverse of f(x)=3x−4f(x) = 3x - 4, in terms of xx.

in terms of x

6

Find the inverse of f(x)=x−12f(x) = \dfrac{x - 1}{2}, in terms of xx.

in terms of x

7

The function f(x)=x2f(x) = x^2 is restricted to x≥0x \ge 0. Write its inverse in terms of xx.

in terms of x

8

With f(x)=5x−2f(x) = 5x - 2 and g(x)=x+25g(x) = \dfrac{x + 2}{5}, find f(g(7))f(g(7)).

9

Find the inverse of f(x)=4−xf(x) = 4 - x, in terms of xx.

in terms of x

10

With f(x)=3x−4f(x) = 3x - 4, find f−1(10)f^{-1}(10).