The equation 3x^2 – 5x + 4 = 0 has roots P and Q, find a quadratic equation with the roots (P + 1/2Q) and (Q + 1/2P)

We know the roots of the equation 3x2 - 5x + 4 = 0 is P & Q, therefore is is equivalent to (x - P)(x - Q) = 0. Expanding the expression we get x2 - x(P+Q) + PQ = 0. Equating coefficents with the original we see that P + Q = 5/3 & PQ = 4/3. The equation of a quadratic is (x- c1)(x-c2). Let c1 = P + 1/2Q & c2 = Q + 1/2P to get [x - (P + 1/2Q)][x - (Q + 1/2P)] = 0. Expanding and simplifying gives x2 - x(P + 1/2Q + Q + 1/ 2P) + (P +1/2Q)(Q + 1/2P) = 0, Simplifiying further gives x2 -x[(P+Q) +((P+Q)/(2PQ))] + (PQ +1 1/4PQ) = 0. Substituting P + Q = 5/3 & PQ = 4/3 to get x2 - x(55/24) + 121/48 = 0. Multiply everything by 48 to get integer values and a final answer 48x2 - 110x + 121 = 0. (did not include long calculation in paragraph as it is not very clear when typed)

SC
Answered by Shafath C. Further Mathematics tutor

3463 Views

See similar Further Mathematics GCSE tutors

Related Further Mathematics GCSE answers

All answers ▸

Why does the discriminant b^2-4ac determine the number of roots of the quadratic equation ax^2+bx+c=0?


Point A lies on the curve y=3x^2+5x+2. The x-coordinate of A is 2. Find the equation of the tangent to the curve at the point A


Prove that tan^2(x)=1/(cos^2(x))-1


A ladder of length 2L and mass m is placed leaning against a wall, making an angle t with the floor. The coefficient of friction between all surfaces is c. At what angle t does the ladder begin to slip?


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:

© 2026 by IXL Learning