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State whether it’s a function or not

State whether it’s a function or not-example-1
User Jesse Hill
by
5.6k points

2 Answers

5 votes

Answer:

Choice C is correct.

Explanation:

We have given a function :

f(x) = 1/x³

We have to find the inverse of function.

let y = f(x) we get,

y = 1/x³

Replacing x and y we get,

x = 1/y³

y³ = 1/x

Taking third roots on both sides we get,

y = 1/∛x

Replacing y to f⁻¹ (x) we get,

f⁻¹ (x)= 1/∛x is the inverse of f(x) = 1/x³.

So, As it is one to one and inverse of function exist so it is a function.

User Anh Nguyen
by
7.4k points
5 votes

Answer:


\boxed{c. \ f^(-1)(x)=\frac{1}{\sqrt[3]{x}}}

Explanation:

Let's find the inverse function of
f(x)=(1)/(x^3) to know what item we must choose as correct. So let's apply this steps:

a) Use the Horizontal Line Test to decide whether
f has an inverse function.

As shown in the graph below there is no any horizontal line that intersects the graph of
f at more than one point. Thus, the function is one-to-one and has an inverse function. Therefore, the inverse is a function..

b) Replace
f(x) by
y in the equation for
f(x).


y=(1)/(x^3)

c) Interchange the roles of
x and
y and solve for
y


x=(1)/(y^3) \\ \\ \therefore y^3=(1)/(x) \\ \\ \therefore y=\frac{1}{\sqrt[3]{x}}

d) Replace
y by
f^(-1)(x) in the new equation.


f^(-1)(x)=\frac{1}{\sqrt[3]{x}}

So the correct option is:


c. \ f^(-1)(x)=\frac{1}{\sqrt[3]{x}}

User Eriktous
by
5.7k points