Integral calculus
The indefinite integral

The indefinite integrals containing quadratic polynomial (trinomial)
Integration by parts rule
The rule for differentiating the product of two differentiable functions leads to the integration by parts formula.
Let  f (x) and g (x) are differentiable functions, then the product rule gives
[ f (x) g (x)]' =  f (x) g (x)'  +  g (x) f ' (x),
by integrating both sides
Since the integral of the derivative of a function is the function itself, then
and by rearranging obtained is
the integration by parts formula.
By substituting  u = f (x) and  v = g (x) then,  du = f ' (x) dx and  dv = g' (x) dx, so that
To apply the above formula, the integrand of a given integral should represent the product of one function and the differential of the other.
The selection of the function u and the differential dv should simplify the evaluation of the remaining integral.
In some cases it will be necessary to apply the integration by parts repeatedly to obtain a simpler integral.
The indefinite integrals containing quadratic polynomial (trinomial)
Recall that the quadratic polynomial  y = ax2 + bx + c  represents the expansion of the translatable form of its source function  y = ax2  in the direction of the coordinate axes, thus
 55.  Evaluate
We solve given integral by separating the derivative of the quadratic polynomial in the numerator, thus
 solution:
therefore, the solution of I2 depend on the leading coefficient a and the vertical translation  y0, i.e.,
 a )   if then,
 b )  if then,
c )  if   y0 = 0  then,
 56.  Evaluate
 Solution:
The integrand function to be real, the quadratic polynomial in the denominator must be positive, therefore
a )   if  a > 0  and   y0 is not then
b )   if  a < 0  and   y0 > then
c )   if  a > 0  and   y0 = then
Functions contents G