(https://qualifications.pearson.com/content/dam/pdf/A-Level/Mathematics/2013/Exam-materials/6666_01_que_20160624.pdf) Question 6.(i)

First split up the fraction into partial fractions as this is more easily integrated. It can be seen that the denominator has factors y and (3y+2), therefore we can say the original fraction is equal to partial fractions (A/y)+(B/(3y+2)). The partial fractions are then recombined by multiplying the numerator and denominator of the first fraction by (3y+2), and y for the second fraction. This gives ((3y+2)A+By)/(y(3y+2)), this is of course equal to the original fraction. It can be seen that the original fraction and our recombined partial fraction have equal denominators, therefore we can write 3y-4=(3y+2)A+By. Our next step is to calculate A and B so that we can rewrite the original fraction as a partial fraction. If y is set to 0 the equation 3y-4=(3y+2)A+By becomes -2=A, and if y is set to-2/3 the equation becomes 9=B, we now have both our values for A and B. The integral can now be rewritten as -(2/y)+9/(3y+2), remembering the standard integral int(a/y)=(a)ln(y) we can then integrate our function, therefore the answer is -2ln(y)+3ln(3y+2)+c .

TJ
Answered by Tom J. Maths tutor

3645 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Solve the equation 2y^(1/2) -7y^(1/4) +3 = 0


Calculate the integral of ln(x)


A and B have coordinates (2,3) and (5,15), respectively. Together they form line l. Find the equation for the line r that goes through C(7,-2) and is perpendicular to l. Give the answer in the format of y=mx+b


Chris claims that, “for any given value of x , the gradient of the curve y=2x^3 +6x^2 - 12x +3 is always greater than the gradient of the curve y=1+60x−6x^2” . Show that Chris is wrong by finding all the values of x for which his claim is not true.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning