To find the antiderivative of a polynomial function, we use the power rule for integration. This involves increasing the exponent by one and dividing by the new exponent. Since the constant of integration \( C \) is given as zero, we omit adding any constant term.
The antiderivative of \( 5x^4 \) is calculated as follows:
\[
\int 5x^4 \, dx = \frac{5}{5}x^{4+1} = x^5
\]
The antiderivative of \( x^9 \) is:
\[
\int x^9 \, dx = \frac{1}{10}x^{9+1} = \frac{1}{10}x^{10}
\]
The antiderivative of \( x^2 - 9x + 18 \) is:
\[
\int (x^2 - 9x + 18) \, dx = \frac{1}{3}x^{3} - \frac{9}{2}x^{2} + 18x
\]
To confirm the antiderivatives, we differentiate each result and check if we obtain the original function.
\[
\frac{d}{dx}(x^5) = 5x^4
\]
This matches the original function \( 5x^4 \).
\[
\frac{d}{dx}\left(\frac{1}{10}x^{10}\right) = x^9
\]
This matches the original function \( x^9 \).
\[
\frac{d}{dx}\left(\frac{1}{3}x^{3} - \frac{9}{2}x^{2} + 18x\right) = x^2 - 9x + 18
\]
This matches the original function \( x^2 - 9x + 18 \).