Respuesta :
The given function is
f(x)= 0.2 x²
Since f(x) will be defined for all real values of x.
So, Domain of f(x) will be ( x| x is a real number.)→This is set builder notation.
Finding the inverse of f(x):
y = 0.2 x²
→ x²= 5 y
→x = [tex]\pm\sqrt{5 y}[/tex]→ → Inverse of f(x)
Replacing x by y and y by x,we get inverse of the given function
y = [tex]\pm\sqrt{5 x}[/tex]→ →Domain x ≥ 0, x∈[0,∞]
Graph of function and its inverse are shown below.
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Answer:
Domain = {x | x≥0 }
Inverse = f⁻¹(x) = [tex]\sqrt 5y[/tex].
Step-by-step explanation:
The given function is [tex]f(x)=0.2x^{2}[/tex]
We know that the domain of all functions is the whole real line.
But as [tex]x^{2}\geq 0[/tex].
So, the domain of f(x) is the positive real line.
Thus, the restriction to the domain of f(x) is {x | x≥0 }.
Now, we will find the inverse of f(x),
[tex]y=0.2x^{2}[/tex]
i.e. [tex]x^{2}=\frac{y}{0.2}[/tex]
i.e. [tex]x^{2}=5y[/tex]
i.e. [tex]x=\sqrt 5y[/tex]
Hence, the inverse of f(x) is f⁻¹(x) = [tex]\sqrt 5y[/tex].
Further, we will check the inverse using composition rule.
i.e. fοf⁻¹(x) = f⁻¹οf(x)
i.e. f(f⁻¹(x)) = f⁻¹(f(x))
i.e. f([tex]\sqrt 5y[/tex]) = f⁻¹([tex]0.2x^{2}[/tex])
i.e. [tex]0.2(\sqrt{5x})^{2}[/tex] = [tex]\sqrt{5\times 0.2x^{2}}[/tex]
i.e. 0.2 × 5x = [tex]\sqrt{x^{2}}[/tex]
i.e. x = x
Hence, we get that the function [tex]f(x)=0.2x^{2}[/tex] has inverse f⁻¹(x) = [tex]\sqrt 5y[/tex].
The graph of the function and its inverse can be seen below.
