Matematică >> funcţii derivabile >> 1
exemple
De exemplu:
1. Derivata funcției \( f : D \rightarrow \mathbb{R} \), \( f(x) = 5x^4 -7x^2 -8x +9 \).
\( f(x) = 5x^4 -7x^2 -8x +9 \)
\( f(x) = 5x^{\color{red}4} -7x^{\color{red}2} -8x^{\color{blue}1} +\color{darkmagenta}9 \)
\( f'(x) = 5 \cdot \color{red}4 \color{dimgray} x^{\color{red}4-1} -7 \cdot \color{red}2 \color{dimgray} x^{\color{red}2-1} -8x^{\color{blue}1-1} +\color{darkmagenta}0 \)
\( f'(x) = 20x^3 -14x -8 \).
1. Derivata funcției \( f : D \rightarrow \mathbb{R} \), \( f(x) = 5x^4 -7x^2 -8x +9 \).
\( f(x) = 5x^4 -7x^2 -8x +9 \)
\( f(x) = 5x^{\color{red}4} -7x^{\color{red}2} -8x^{\color{blue}1} +\color{darkmagenta}9 \)
\( f'(x) = 5 \cdot \color{red}4 \color{dimgray} x^{\color{red}4-1} -7 \cdot \color{red}2 \color{dimgray} x^{\color{red}2-1} -8x^{\color{blue}1-1} +\color{darkmagenta}0 \)
\( f'(x) = 20x^3 -14x -8 \).
exerciții
Derivata funcţiei \( f : D \rightarrow \mathbb{R} \),
\(f(x)=7x^{4}+9x^{3}+5x\)
este:
\(f'(x)=\)\(28x^{3}+27x^{2}+5\).
Avem:
\(f(x) = 7x^{4}+9x^{3}+5x\)
\(f(x) = 7x^{ \color{red}4 \color{dimgray}}+9x^{ \color{red}3 \color{dimgray}}+5x^{ \color{blue}1 \color{dimgray}}\)
\(f'(x) = 7\cdot \color{red}4 \color{dimgray}x^{ \color{red}4-1 \color{dimgray}}+9\cdot \color{red}3 \color{dimgray}x^{ \color{red}3-1 \color{dimgray}}+5x^{ \color{blue}1-1 \color{dimgray}}\)
\(f'(x) = \)\(28x^{3}+27x^{2}+5\).