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

6697 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Use the factor theorem to show that (x+2) is a factor of g(x)= 4x^3 - 12x^2 - 15x + 50


Solve algabraically: 6a+b=16 and 5a-2b=19


Put the following in order of size, smallest first: 8/sqrt3, sqrt6*sqrt2, sqrt48-sqrt27


f(x)=cos(x), g(x)=2+cos(x-1), state g(x) as a vector applied to f(x)


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