What is (1+√2) (1-√2)?

Question

(1+√2) (1-√2)
are my steps wrong?
1 times 1 = 1 
+
1 times -root2 = -root 2
+
positive root2 times 1 = positive root 2 
then
For the last step I got that -√2 times √2 = -2 right? 
should be 1-root 2 +root 2, those cancel, and -root 2 at the end. 
total should be 1-2 = -1 

WHAT????? where is the mistake?

wirehawkboston · Accepted Answer

(1+√2)
(1-√2)
______

1 - sq rt of 2

   +sq rt pf 2

                     - sq rt of 2 sq =- 2


Ans 1 - 2 = -1

Nik B. · Answer

(1+â2) (1-â2) =
1 - â2 + â2 - (â2)Â² =
1 - 2 = 
-1

? · Answer

YOUR STEPS ARE RIGHT

(1+â2) (1-(1+â2)

=[1]^2--[â2 ]^2

=1--2

=  --1

Guillermo · Answer

You're rigth!

(1+â2)*(1-â2) = 1 - â2 + â2 - 2 = 1 - 2 = - 1

chuy_mck92 · Answer

i found your problem! -â2 times â2 does not equal -2 

it equals â2^2 (squared)
and thats just 2
then youll be left with 1-2 and then -1 as your answer

Anonymous · Answer

No mistake - - - (a+b)(a-b) = a^2-b^2

in your problem a^2 = 1 and b^2 = 2

Marie · Answer

Simple FOIL problem! The answer IS indeed -1!

Anonymous · Answer

Who says -1 is wrong?

Trending News

What is (1+√2) (1-√2)?

8 Answers