Все решения в приложении.
1). 3x^2+7x+2=0; D=7^2-4*3*2=49-24=25; x1=(-7-5)/6, x2=(-7+5)/6. x1= -2, x2= -1/3. 3x^2+7x+2=3*(x+1/3)*(x+2)=(3x+1)*(x+2). 2).c^2-14c+48=0; D=(-14)^2-4*1*48=196-192=4; c1=(14-2)/2, c2=(14+2)/2. c1=6, c2=8. c^2-14c+48=(c-6)*(c-8).
(а-3)²=а<u />²-6а+9
(2х+у)²=4х²+4ху+²
(5в-4х)(5в+4х)=25в²-16х²
Sin2x+cos2x+1=0
2sinxcosx+cos²x-sin²x+sin²x+cos²x=0
2sinxcosx+2cos²x=0
2cosx(sinx+sin(π/2-x)=0
2cosx*2sinπ/4cos(x-π/4)=0
2*2*√2/2cosxcos(x-π/4)=0
2√2cosxcos(x-π/4)=0
cosx=0⇒x=π/2+πn
cos(x-π/4)=0⇒x-π/4=π/2+πn⇒x=3π/4+πn
<span>у=-х^3/3 +х^2 +1; x</span>∈<span> [ -3; 1]
y '(x) = 3x^3/3 + 2x = x^2 + x = x(x+1);
y '(x) = 0;
x(x+1) = 0; </span>∈ [ - 3; 1]<span>
x = - 1; x = 0. </span><span>∈ [ - 3; 1]</span><span>
y ' + - +
________(-1)________0________x
y возр убыв возраст
х = - 1 - точка максимума,
х = 0 - точка минимума.
у наиб.= (-1)^3/3 + (-1)^2 + 1= - 1/3 + 1+1= 5/3
у наим.=0^3/3 + 0^2 + 1 = 1.</span>