what would 1/(f(c)) =

Question

f(x) = x ^ 3 + 9x + 13

what would 1/(f(c)) =

Answer 1

Hi Zam,

f(x) means that you can plug any number in the place of "x" and replace x with the number in the rest of the equation (x³ + 9x + 13 in this problem). For example, for f(x) = x³ + 9x + 13, f(1) = 1³ + 9(1) + 13 = 23. Notice how x was replaced with 1.

Likewise for f(c), we substitute x for c and get f(c) = c³ + 9c + 13. So 1/(f(c)) = 1 / (c³ + 9c + 13).

Hope this helps,

Akshat Y.

Answer 2

Since f(x) = x³ + 9x + 13, simple substitution (change of variables) yields

f(c) = c³ + 9c + 13

Thus, the multiplicative inverse or reciprocal is simply

1/f(c) = 1/(c³ + 9c + 13)