Question

If x = −1, then what is the value of the function f(x) = x^3 + 4x +12

Answer 1

Answer:

7

Step-by-step explanation:

-1^3+4×-1+12

-1-4+12

-5+12

7

Answer 2

Answer:

Required value of f(x) is 7.

Step-by-step explanation:

Given function is $f(x) = {x}^{3} + 4x + 12$ and $x = - 1$

It means if f(x)=0 then (-1) is the root of f(x)

Now we are putting $x = - 1$

and get$f( - 1) = {( - 1)}^{3} + 4 \times ( - 1) + 12$

$f( - 1) = - 1 - 4 + 12 = 7$

So value of f(x) is 7 if x=-1

By this process we can found value of any function if value of x is given.

For example,

Let g(x)$= {x}^{2} + 4x$

and x=5

So,$g(5) = {5}^{2} + 4 \times 5 = 25 + 20 = 45$