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

5943 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

A curve has parametric equations -> x = 2cos(2t), y = 6sin(t). Find the gradient of the curve at t = π/3.


Given that y= x^(-3/2) + (1/2)x^4 + 2, Find: (a) the integral of y (b) the second differential of y


Core 1 question: Draw the graph "y = 12 - x - x^2"


How would you differentiate and integrate 2x^3?


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