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

7338 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

(x+2)/(x-3) - (x-1)/(x+3) can be written in the form (ax+b)/(x^2-9). Work out the value of a and the value of b.


Using the substitution method, solve the following simultaneous equations 2y+3x=14 and 6x-y=8


What is the general equation for a straight graph line and what does each part represent?


Solve the simultaneous equation: 2x - 5y = 9 , x + 6y = -4


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