Решите уравнение f(x)=0: 1)f (x)= 3x^2+8x+2; 2) f(x)= -6x^2 +13 -1; 3) f(x)= (3\2) * x^2...

Question

Решите уравнение f(x)=0: 1)f (x)= 3x^2+8x+2; 2) f(x)= -6x^2 +13 -1; 3) f(x)= (3\2) * x^2 + 4x -1; 4) f(x)= -0,5x^2 - 4x + 0,1.

Answer 1

1) f (x) = 3x^2 + 8x + 2
f'(x) = 6x + 8
f' (x) = 0 => 6x + 8 = 0
6x = -8
x = -8/6
x = -4/3 = - 1 целая 1/3
2) f'(x) = -12x
-12x = 0
x = 0
3) f'(x) = 3x + 4
3x + 4 = 0
3x = - 4
x = - 4/3
4) f'(x) = -x - 4
- x - 4 = 0
- x = 4 | × (-1)
x = - 4