C h a p t e r 3 S e c t i o n 2 {\displaystyle \mathbf {Chapter3Section2} } d d x [ c ] = 0 {\displaystyle {\frac {d}{dx}}[c]=0} d d x [ c ⋅ f ( x ) ] = c ⋅ d d x [ f ( x ) ] {\displaystyle {\frac {d}{dx}}[c\cdot f(x)]=c\cdot {\frac {d}{dx}}[f(x)]} d d x [ f ( x ) ± g ( x ) ] = d d x [ f ( x ) ] ± d d x [ g ( x ) ] {\displaystyle {\frac {d}{dx}}[f(x)\pm g(x)]={\frac {d}{dx}}[f(x)]\pm {\frac {d}{dx}}[g(x)]} d d x [ a x ] = ln ( a ) a x {\displaystyle {\frac {d}{dx}}[a^{x}]=\ln(a)a^{x}} d d x [ e x ] = e x {\displaystyle {\frac {d}{dx}}[e^{x}]=e^{x}} P o w e r R u l e {\displaystyle \color {Blue}PowerRule} d d x [ x n ] = n ⋅ x n − 1 {\displaystyle {\frac {d}{dx}}[x^{n}]=n\cdot x^{n}-1} P r o d u c t R u l e {\displaystyle \color {Blue}ProductRule} d d x [ f ⋅ g ] = d d x [ f ] ⋅ g + d d x [ g ] ⋅ f {\displaystyle {\frac {d}{dx}}[f\cdot {g}]={\frac {d}{dx}}[f]\cdot {g}+{\frac {d}{dx}}[g]\cdot {f}} Q u o t i e n t R u l e {\displaystyle \color {Blue}QuotientRule} d d x [ f g ] = d d x [ f ] ⋅ g − d d x [ g ] ⋅ f g 2 {\displaystyle {\frac {d}{dx}}[{\frac {f}{g}}]={\frac {{\frac {d}{dx}}[f]\cdot {g}-{\frac {d}{dx}}[g]\cdot {f}}{g^{2}}}} E x .1 {\displaystyle \mathbf {Ex.1} } f ( x ) = x ⋅ e x {\displaystyle f(x)=x\cdot {e^{x}}} f ′ ( x ) = 1 ⋅ e x + x ⋅ e x {\displaystyle f^{\prime }(x)=1\cdot {e^{x}}+x\cdot {e^{x}}} E x .2 {\displaystyle \mathbf {Ex.2} } f ( t ) = t ( a + b t ) {\displaystyle f(t)={\sqrt {t}}(a+bt)} f ′ ( t ) = 1 2 t ( a + b t ) + t t ( b ) {\displaystyle f^{\prime }(t)={\frac {1}{2{\sqrt {t}}}}(a+bt)+t{\sqrt {t}}(b)} E x .3 {\displaystyle \mathbf {Ex.3} } i f f ( x ) = x ⋅ g ( x ) {\displaystyle if\,f(x)={\sqrt {x}}\cdot {g(x)}} g ( 4 ) = 2 {\displaystyle g(4)=2} g ′ ( 4 ) = 3 {\displaystyle g^{\prime }(4)=3} f ′ ( x ) = 1 1 2 x ⋅ g ( x ) + x ⋅ g ′ ( x ) {\displaystyle f^{\prime }(x)=1{\sqrt {1}}{2{\sqrt {x}}}\cdot {g(x)}+{\sqrt {x}}\cdot {g^{\prime }(x)}}