а)f(3)= -(3²)-3+12=-9-3+12=0
f(-5)= -(-5²)+5+12=-25+5+12= -8
в) 6= -х²-х+12
-х²-х+6=0
х²+х-6=0
D=1+6*4=25
x= (-1+5)/2=2
x= (-1-5)/2=-3
(2;6) и (-3;6)
а)f(3)= -(3²)-3+12=-9-3+12=0
f(-5)= -(-5²)+5+12=-25+5+12= -8
в) 6= -х²-х+12
-х²-х+6=0
х²+х-6=0
D=1+6*4=25
x= (-1+5)/2=2
x= (-1-5)/2=-3
(2;6) и (-3;6)