bonsoir
f (x) = ( x - 5 )² - 36
f (x) = x² - 10 x + 25 - 36
f ( x) = x² - 10 x - 11
f ( x) = ( x - 5 - 6 ) ( x - 5 + 6 )
f (x) = ( x - 11 ) ( x + 1 )
f (x) = 0
( x - 11 ) ( x + 1 ) = 0
x = 11 ou - 1
f (x) = - 36
( x - 5 )² - 36 = - 36
( x - 5 )² - 36 + 36 = 0
( x - 5 )² = 0 ⇔ x = 5
( x - 5 )² - 36 = - 11
( x - 5 )² - 36 + 11 = 0
( x - 5 )² - 25 = 0
( x - 5 - 5 ) ( x - 5 + 5) = 0
x ( x - 10 ) = 0
x = 0 ou 10
f (x) = - 10 x
x² - 10 x - 11 = - 10 x
x² - 10 x + 10 x = 11
x² = 11
x = √ 11 ou - √11
