- Started with
\[\cos \left(x + \varepsilon\right) - \cos x\]
22.8
- Using strategy
rm 22.8
- Applied cos-sum to get
\[\color{red}{\cos \left(x + \varepsilon\right)} - \cos x \leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x\]
18.7
- Applied associate--l- to get
\[\color{red}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) - \cos x} \leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon + \cos x\right)}\]
18.7
- Using strategy
rm 18.7
- Applied flip-- to get
\[\color{red}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon + \cos x\right)} \leadsto \color{blue}{\frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\sin x \cdot \sin \varepsilon + \cos x\right)}^2}{\cos x \cdot \cos \varepsilon + \left(\sin x \cdot \sin \varepsilon + \cos x\right)}}\]
18.7
- Using strategy
rm 18.7
- Applied add-exp-log to get
\[\color{red}{\frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\sin x \cdot \sin \varepsilon + \cos x\right)}^2}{\cos x \cdot \cos \varepsilon + \left(\sin x \cdot \sin \varepsilon + \cos x\right)}} \leadsto \color{blue}{e^{\log \left(\frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\sin x \cdot \sin \varepsilon + \cos x\right)}^2}{\cos x \cdot \cos \varepsilon + \left(\sin x \cdot \sin \varepsilon + \cos x\right)}\right)}}\]
21.1
- Applied simplify to get
\[e^{\color{red}{\log \left(\frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\sin x \cdot \sin \varepsilon + \cos x\right)}^2}{\cos x \cdot \cos \varepsilon + \left(\sin x \cdot \sin \varepsilon + \cos x\right)}\right)}} \leadsto e^{\color{blue}{\log \left(\left(\cos \varepsilon \cdot \cos x - \cos x\right) - \sin x \cdot \sin \varepsilon\right)}}\]
17.1
- Applied taylor to get
\[e^{\log \left(\left(\cos \varepsilon \cdot \cos x - \cos x\right) - \sin x \cdot \sin \varepsilon\right)} \leadsto e^{\log \left(\frac{-1}{2} \cdot {\varepsilon}^2 - \sin x \cdot \sin \varepsilon\right)}\]
17.3
- Taylor expanded around 0 to get
\[e^{\log \left(\color{red}{\frac{-1}{2} \cdot {\varepsilon}^2} - \sin x \cdot \sin \varepsilon\right)} \leadsto e^{\log \left(\color{blue}{\frac{-1}{2} \cdot {\varepsilon}^2} - \sin x \cdot \sin \varepsilon\right)}\]
17.3
- Applied simplify to get
\[e^{\log \left(\frac{-1}{2} \cdot {\varepsilon}^2 - \sin x \cdot \sin \varepsilon\right)} \leadsto \left(\varepsilon \cdot \frac{-1}{2}\right) \cdot \varepsilon - \sin \varepsilon \cdot \sin x\]
0.1
- Applied final simplification