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Verify that f and g are inverse functions of each other, where f(x) = x-74, g(x) = 4x + 7 - Mathematics and Statistics

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Question

Verify that f and g are inverse functions of each other, where f(x) = `(x - 7)/4`, g(x) = 4x + 7

Sum

Solution

f(x) = `(x - 7)/4`, g(x) = 4x + 7

f[g(x)] = `(g(x) -7)/4`

=` (4x + 7 - 7)/4`

= x

f[g(x)] = f(4x + 7)

Replacing x by f(x), we get

`g[f(x)]= 4f(x) + 7= 4((x - 7)/4) + 7 = x`

∴ f and g are inverse functions of each other.

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Algebra of Functions
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Chapter 6: Functions - Exercise 6.2 [Page 127]

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