Using partial fractions find the integral of (15-17x)/((2+x) (1-3x)^2 )

First seperate the function into the form A/(2+x)  +   B/(1-3x)   +   C/(1-3x)2 . Find A B and C by equating the intergral to {A(1-3x)2 +B(1-3x)(2+x) +C(2+x)}/(2+x)(1-3x)2  . Cancelling the denominators gives an equation equal to 15-7x, and in terms of A, B and C. We then use comparison of the right and left hand sides to find A, B and C. By subsituting x=-2, x=1/3 and by comparing coefficients of x2 the values of A B and C can be found. Subbing these into the partial fraction equation(1st line) we can then intergrate this expression, using the fact that the intergral of 1/x is equal to ln(x). 

SB

Related Maths A Level answers

All answers ▸

How to plot quadratic functions, e.g. F(x)= x^2 + 2x +1


Find the integral of the function y = ln(x)


Solve the differential equation dx/dt=-6*x , given when t=0 x=7.


What is the difference between mutually exclusive and indepedent events?