The quadratic equation 2x^2 + 8x + 1 = 0 has roots a and b. Write down the value of a + b, a*b and a^2 + b^2.

Using Vieta's formulas, which make the correspondence between the sums and products of the roots of a polynomial and its coefficients, we can deduce that a + b = (-8)/2 = -4, ab = 1/2 =0.5 and a^2 + b^2 = (a+b)^2 - 2ab = (-4)^2 - 2*0.5 = 16 - 1 = 15. 

AI
Answered by Andreea I. Maths tutor

6134 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Find the coordinates of the turning points of the curve y = 4/3 x^3 + 3x^2-4x+1


Differentiate 5x^2 + 11x + 5 with respect to x


find the integral of 1+3 root x


Solve for x, between 0 and 360 degrees, 4cos2 (x) + 7sin (x) – 2 = 0


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