Question

If f(x) = x² + 6 and g(x) = 2x + 1 then g o f is

Ans: ?

g o f means g[f(x)]

Answer 1

Question :-

If f(x) = x² + 6 and g(x) = 2x + 1 then g o f is -

g o f means g[f(x)]

Answer :-

→ g o f = 2x² + 13

→ f o g = 4x² + 4x + 7

Solution :-

If any two functions are given ,

let f(x) be a function and g(x) also a function so when we find f o g then we put value of g(x) at the place of x in g(x)

like that g{f(x)}

Therefore ,

According to the question,

f(x) = x² + 6 and g(x) = 2x + 1

Then ,

g o f = g{f(x)}

Put the value of f(x) in g(x)

→ g o f = 2 ( x² + 6 )+1

→ g o f = 2x² + 12 + 1

→ g o f = 2x² + 13

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If we need to find f o g means f{g(x)} ,

then put the value of g(x) in f(x) ,

therefore ,

→ f o g =( 2x +1 )² + 6

→ f o g = 4x² +1+4x+ 6

→ f o g = 4x² + 4x + 7

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