Question

Найдите производную функцию а) y=5/7x^4+4x^3+2/3x-2 b)y=7кореньx+0,5cosx-3tgx c)y=кореньx(5x-3) d)y=-3x/x^2+3x

Answer 1

а)

$\displaystyle y`=(\frac{5}{7}x^4+4x^3+\frac{2}{3}x-2)`=\frac{20}{7}x^3+12x^2+\frac{2}{3}$

б)

$\displaystyle y`=(7\sqrt{x}+0.5cosx-3tgx)`=\frac{7}{2\sqrt{x}}-0.5sinx-\frac{3}{cos^2x}$

c)

$\displaystyle y`=(\sqrt{x} (5x-3))`=(\sqrt{x})`*(5x-3)+\sqrt{x}(5x-3)`=\\\\=\frac{5x-3}{2\sqrt{x} }+5\sqrt{x} =\frac{5x-3+10x}{2\sqrt{x}}=\frac{15x-3}{2\sqrt{x}}$

d)

$\displaystyle y`=(\frac{-3x}{x^2+3x})`=\frac{(-3x)`(x^2+3x)-(-3x)(x^2+3x)`}{(x^2+3x)^2}=\\\\=\frac{-3(x^2+3x)+3x(2x+3)}{(x^2+3x)^2}=\frac{-3x^2-9x+6x^2+9x}{(x^2+3x)^2}=\\\\=\frac{3x^2}{(x^2+3x)^2}$