Problem
13. Compute the derivatives of the following functions (a) \( f(x)=6 e^{x^{4}+x^{2}} \) (b) \( f(x)=\ln \left(x^{2}+1\right) \)
Solution
Step 1 ：\( \frac{d}{dx}(6 e^{x^{4}+x^{2}}) = 6 \frac{d}{dx} (e^{x^{4}+x^{2}})\)
Step 2 ：\( = 6e^{x^{4}+x^{2}} \frac{d}{dx}(x^{4}+x^{2}) \)
Step 3 ：\( = 6e^{x^{4}+x^{2}}(4x^{3}+2x) \)
