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\mathrm{f}^{\prime}(\mathrm{g}(2)) \approx \mathrm{f}^{\prime}(2) \approx 0,(\text { fog })^{\prime}(2)=\mathrm{f}^{\prime}(\mathrm{g}(2)) \cdot \mathrm{g}^{\prime}(2) \approx 0