Question

which of the following choices will evaluate the function f(x)= -(-x), when x=-3

A. 3
B. -1
C. -3
D. None of these choices are correct

Answer 1

Option C

The value of function when x = -3 is f(-3) = -3

Solution:

Given function is:

$f(x) = -( -x )$

We have to evaluate the given function for x = -3

We can find the value of f(x) when x is equal to -3 by substituting -3 in place of x

Substitute x = - 3 in given function

$f( -3 ) = -(- (-3))$

Solve for the innermost bracket

We have -3 inside the bracket and negative sign outside the bracket

We know that negative sign multiplied with another negative sign will give positive sign

Therefore,

$f( -3 ) = -(3)$

Now we have 3 inside the bracket and negative sign outside the bracket

Negative sign multiplied with positive sign will give negative sign

Therefore,

$f( -3 ) = -(3) = -3\\\\f(-3) = -3$

Thus value of function when x = -3 is f(-3) = -3