The equation 2x^2 + 2kx + (k + 2) = 0, where k is a constant, has two distinct real roots. Show that k satisfies k^2 – 2k – 4 > 0

Two distinct real roots means that we can use b^2-4ac>0 relationship for any ax^2+bx+c equation. Apply the above gives, 4k^2 - 42(k+2)>0 Simplifying gives, k^2 - 2k -4 >0

AT
Answered by Andreas T. Maths tutor

11372 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Differentiate sin(x)cos(x) with respect to x?


Why does exp(x+y) NOT equal exp(x)+exp(y)? [A-level Maths and Further Maths common mistake]


The point A lies on the curve with equation y = x^(1/2). The tangent to this curve at A is parallel to the line 3y-2x=1. Find an equation of this tangent at A. (PP JUNE 2015 AQA)  


A line has equation y = 2x + c and a curve has equation y = 8 − 2x − x^2, if c=11 find area between the curves


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences