Question

2. Решите уравнение:

a) x-7x²-6=0

6) (x²-2)²+2(x²-2)-3-0​

Answer 1

Ответ:

а) f '(x) =(7x² -56x +8) ' =(7x²) ' -(56 x)' +(8) ' =7*(x²) ' -56(x)' +0 =14x -56 =14(x-4) ;

f '(4) =14(4 -4) = 0.

б) f '(x) =(√x -16x) ' =(x^(1/2) -16x)'= (x^(1/2))' -(16x)' =1/2*x^(-1/2) -16(x)' =1/2*1/(x)^(1/2) -16

=1/(2√x) -16 ; f '(1/4) =1/(2√(1/4)) -16 = 1 -16 = -15 .