PDA

View Full Version : (1-2sqrt3)^2



ginny1029
05-20-2009, 12:59 AM
i did the following:

(1-2sqrt3) (1-2sqrt3)

1times 1=1
1 times -2sqrt2 = -2sqrt 3
-2sqrt3 times 1 = -2sqrt3
-2sqrt3 time - 2sqrt3 = 4sqrt 3

so I have
1 - 2sqrt3 - 2sqrt3 + 4 sqrt 3

which leaves me with 1

which is very wrong

help?

Subhotosh Khan
05-20-2009, 07:25 AM
i did the following:

(1-2sqrt3) (1-2sqrt3)

1times 1=1
1 times -2sqrt2 = -2sqrt 3
-2sqrt3 times 1 = -2sqrt3
-2sqrt3 time - 2sqrt3 = 4sqrt 3 <<< Incorrect

-2 sqrt3 time - 2 sqrt3= (-2)(-2) (?3)(?3) = (4) (3) = 12

so I have
1 - 2sqrt3 - 2sqrt3 + 4 sqrt 3

which leaves me with 1

which is very wrong

help?