Show that x^2+6x+11 can be written in as (x+p)^2+q, where p and q are integers to be found.

To start, we need to complete the square of the equation. To do this, we divide the coefficient of x by 2. Here, 6/2=3. We then find (x+3)^2, which gives us the first part of the equation we want to express, but also leaves us with something extra. Expanding out (x+3)^2 gives us x^2+6x+9. Here we have what we were trying to express but with the extra part 9, so we can write (x^2+6x)=(x+3)^2-9.
Substituting this back into our original equation, we have (x+3)^2-9+11, which equals (x+3)^2+2.Therefore, p=3, q=2.

HE
Answered by Hannelore E. Maths tutor

8970 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

The point P lies on a curve with equation: x=(4y-sin2y)^2. (i) Given P has coordinates (x, pi/2) find x. (ii) The tangent to the curve at P cuts the y-axis at the point A. Use calculus to find the coordinates of the point A.


Integrate Sin(x)Cos(x)dx.


The points A and B have coordinates (1, 6) and (7,− 2) respectively. (a) Find the length of AB.


How do I simplify (1 / [1 + cos(x) ] ) + (1 / [1 - cos(x) ] )?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences