1) f '(x) = (3x^6)' +(x^4/4)' - (2x²)' +(5x)' = 18x^5 +x³ -4x +5
2) Ищем по формуле (UV)'= U'V + UV'
f '(x) = (2-5x)'*√x + (2-5x)*(√x)' = -5√x + (2-5x)*1/2√x= (-10x +2 -5x)/2√х = =(2-15х)/2√х
3) Ищем по формуле (U/V)' = (U'V - UV')/V²
f'(x) =((x² -8x)' *(x+2) - (x² -8x)*(x+2)' )/(x +2)²=
=((2x -8)(x+2) - (x² -8x)*1)/(x+2)² = (2x² -8x +4x -16 -x² +8x)/(x+2)²=
=( x² +4x -16)/(x+2)²
4) f(x) = 4x^-2 - 5x^-4
f'(x) =(4x^-2)' - (5x^-4)' = -8x^-3 + 20 x^-5 = -8/x³ + 20/x^5