$\int 2 x\left(x^{2}+2\right)^{-4} d x=\square$
\(\boxed{\int 2 x\left(x^{2}+2\right)^{-4} d x = \frac{1}{-3} (x^2 + 2)^{-3} + C}\)
Step 1 :Let \( u = x^2 + 2 \). Then, \( du = 2x dx \).
Step 2 :Rewrite the integral in terms of \( u \): \( \int 2 x\left(x^{2}+2\right)^{-4} d x = \int u^{-4} du \)
Step 3 :Integrate \( u^{-4} \) with respect to \( u \): \( \int u^{-4} du = \int u^{-4 + 1} \frac{1}{-4 + 1} du = \frac{1}{-3} u^{-3} \)
Step 4 :Substitute back \( u = x^2 + 2 \): \( \frac{1}{-3} u^{-3} = \frac{1}{-3} (x^2 + 2)^{-3} \)
Step 5 :\(\boxed{\int 2 x\left(x^{2}+2\right)^{-4} d x = \frac{1}{-3} (x^2 + 2)^{-3} + C}\)