Let 2 + 3x3 = t
∴ 9x2 dx = dt
\(\Rightarrow \frac{x^2}{(2+3x^3)}dx=\frac{1}{9}\int\frac{dt}{(t)^3}\)
= \(\frac{1}{9}\bigg[\frac{t^{-2}}{-2}\bigg]+C\)
= \(\frac{-1}{18}\bigg(\frac{1}{t^2}\bigg)+C\)
=\(\frac{-1}{18(2+3x^3)^2}+C\)
What is the Planning Process?
Given below is the list of the different methods of integration that are useful in simplifying integration problems:
If f(x) and g(x) are two functions and their product is to be integrated, then the formula to integrate f(x).g(x) using by parts method is:
∫f(x).g(x) dx = f(x) ∫g(x) dx − ∫(f′(x) [ ∫g(x) dx)]dx + C
Here f(x) is the first function and g(x) is the second function.
The formula to integrate rational functions of the form f(x)/g(x) is:
∫[f(x)/g(x)]dx = ∫[p(x)/q(x)]dx + ∫[r(x)/s(x)]dx
where
f(x)/g(x) = p(x)/q(x) + r(x)/s(x) and
g(x) = q(x).s(x)
Hence the formula for integration using the substitution method becomes:
∫g(f(x)) dx = ∫g(u)/h(u) du
This method of integration is used when the integration is of the form ∫g'(f(x)) f'(x) dx. In this case, the integral is given by,
∫g'(f(x)) f'(x) dx = g(f(x)) + C