\[f(x) = 4x^{4} - 3x^{2} + 14;\]
\[f^{'}(x) = 16x^{3} - 6x;\]
\[f^{'}\left( - \frac{1}{2} \right) = 16 \cdot \left( - \frac{1}{8} \right) - 6 \cdot \left( - \frac{1}{2} \right) =\]
\[= - 2 + 3 = 1.\]