Question

Допоможіть 25 і 26 завдання))дуже прошу

Answer 1

25

1) f(x) = 0  - 4 корня

2) f(x) ≤ 0   ответ - 7 целых чисел

$26)x+\frac{1}{x}=4\\\\(x + \frac{1}{x})^{2}=4^{2}\\\\x^{2}+2*x*\frac{1}{x} +\frac{1}{x^{2} } =16\\\\x^{2}+2+\frac{1}{x^{2}}=16\\\\x^{2}+\frac{1}{x^{2}}=14$

$x^{3}+\frac{1}{x^{3}} \\\\(x+\frac{1}{x})^{3}=4^{3}\\\\x^{3}+3*x^{2}*\frac{1}{x}+3*x*\frac{1}{x^{2}} +\frac{1}{x^{3}} =64\\\\x^{3}+3x+3*\frac{1}{x}+\frac{1}{x^{3}}=64\\\\x^{3}+3(x+\frac{1}{x})+\frac{1}{x^{3}}=64\\\\\ x^{3}+3*4+\frac{1}{x^{3}} =64\\\\x^{3} +12+\frac{1}{x^{3}}=64\\\\x^{3}+\frac{1}{x^{3}} =52$