- Started with
\[\cos \left(x + \varepsilon\right) - \cos x\]
30.9
- Using strategy
rm 30.9
- Applied cos-sum to get
\[\color{red}{\cos \left(x + \varepsilon\right)} - \cos x \leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x\]
2.6
- Applied associate--l- to get
\[\color{red}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) - \cos x} \leadsto \color{blue}{\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon + \cos x\right)}\]
2.6
- Using strategy
rm 2.6
- Applied add-log-exp to get
\[\cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon + \color{red}{\cos x}\right) \leadsto \cos x \cdot \cos \varepsilon - \left(\sin x \cdot \sin \varepsilon + \color{blue}{\log \left(e^{\cos x}\right)}\right)\]
2.7
- Applied add-log-exp to get
\[\cos x \cdot \cos \varepsilon - \left(\color{red}{\sin x \cdot \sin \varepsilon} + \log \left(e^{\cos x}\right)\right) \leadsto \cos x \cdot \cos \varepsilon - \left(\color{blue}{\log \left(e^{\sin x \cdot \sin \varepsilon}\right)} + \log \left(e^{\cos x}\right)\right)\]
2.8
- Applied sum-log to get
\[\cos x \cdot \cos \varepsilon - \color{red}{\left(\log \left(e^{\sin x \cdot \sin \varepsilon}\right) + \log \left(e^{\cos x}\right)\right)} \leadsto \cos x \cdot \cos \varepsilon - \color{blue}{\log \left(e^{\sin x \cdot \sin \varepsilon} \cdot e^{\cos x}\right)}\]
2.8
- Applied add-log-exp to get
\[\color{red}{\cos x \cdot \cos \varepsilon} - \log \left(e^{\sin x \cdot \sin \varepsilon} \cdot e^{\cos x}\right) \leadsto \color{blue}{\log \left(e^{\cos x \cdot \cos \varepsilon}\right)} - \log \left(e^{\sin x \cdot \sin \varepsilon} \cdot e^{\cos x}\right)\]
3.0
- Applied diff-log to get
\[\color{red}{\log \left(e^{\cos x \cdot \cos \varepsilon}\right) - \log \left(e^{\sin x \cdot \sin \varepsilon} \cdot e^{\cos x}\right)} \leadsto \color{blue}{\log \left(\frac{e^{\cos x \cdot \cos \varepsilon}}{e^{\sin x \cdot \sin \varepsilon} \cdot e^{\cos x}}\right)}\]
3.1
- Applied simplify to get
\[\log \color{red}{\left(\frac{e^{\cos x \cdot \cos \varepsilon}}{e^{\sin x \cdot \sin \varepsilon} \cdot e^{\cos x}}\right)} \leadsto \log \color{blue}{\left(e^{\left(\cos \varepsilon \cdot \cos x - \cos x\right) - \sin x \cdot \sin \varepsilon}\right)}\]
2.8