1. f(x) = ctg x + 2x^3 + √x - 50
f'(x) =- 1/sin^2 x + 6x^2 + 1/2√x
2. √(2x^2-3x) =√(x^2+ x)
ОДЗ:
x(2x - 3)= 0
x≠ [ 0; 3/2]
x^2+ x = 0
x(x+1) =0
x =0 x= - 1;
x ≠ [-1;0]
2x^2 - 3x = x^2 + x
x^2 -4x = 0
x(x-4) = 0
x= 0 x= 4
4. 5^2x = 125
5^2x = 5^3
2x=3
x= 1,5.
Решение
lim x-> 1 (x³-1)/(x²-1) =lim x-->1 [(x - 1)(x² + x + 1)] / [(x - 1)*(x + 1)] =
= limx ->1 (x² + x + 1)/(x + 1) = (1² + 1 + 1) / (1 + 1) = 3/2 = 1,5