Show that the function f(x) = x^2 + 2x + 2 is always positive for real values of x

By completing the square we find that f(x) = x2 + 2x + 2 = (x+1)2 + 1Since (x+1)2 is a number that has been squared, it must be greater than or equal to zero. Therefore, f(x) = (x+1)2 + 1 must be greater than zero because adding a positive number to a number that is greater than or equal to zero will always give a positive number.

BC
Answered by Bradley C. Maths tutor

7363 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

A particle is moving along a straight line. The fixed point O lies on this line. The displacement of the particle from O at time t seconds is s metres where s = 2t3 – 12t2 + 7t(a) Find an expression for the velocity, v m/s, of the particle at time t.


x - 2y = 1 , x^2 + y^2 = 13 find the solutions to this quadratic equation


Solve the following quadratic equation x^(2)+7x+12


Solve the simultaneous equations: 3x-y=1, x^2+y^2=5


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