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

12830 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Given y=2x(x^2-1)^5, show that dy/dx = g(x)(x^2-1)^4 where g(x) is a function to be determined.


Particles P and Q of masses 0.4kg and m kg are joined by a light inextensible string over a smooth pulley. When released Q accelerates downward at 2.45ms^-2. Find m.


You are given the equation of the line y=x^3+x^2-2x. Find the stationary points of the curve and determine the maximum and minimum points and find where it crosses the x-axis and thus sketch the graph


How many solutions are there of the equation a+b+c=12, where a,b,c are non-negative integers?


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