ukmt question

[steep forge]

what don't you get

anything squared >= 0

[cerulean drift]

yeah

but then the whole expression >= -5

[steep forge]

since when you factorise

you have -5 at the end

[cerulean drift]

yeah

[steep forge]

if (a+b)^2 >= 0
(a+b)^2 -5 >= -5

[cerulean drift]

ohh

[cerulean drift]

yeah ok but then the next part

[steep forge]

inside the bracket has to equal 0

[cerulean drift]

so we're saying -5 is the min value?

[cerulean drift]

and then we take away -5 but then do u plug it back in?

[steep forge]

wdym

[cerulean drift]

how do we know it's achieved for x+y+3=0

[steep forge]

since the smallest value a square can be is 0