1
f(x)=(2+√x)(2-√x)=4-x
f`(x)=(4)`-(x)`=0-1=-1
2
f(x)=(3x-5)(3x+1)=9x²-12x-5
f`(x)=(9x²)`-(12x)`-(5)`=18x-12
3
f(x)=(2x+3)/(3x+5)
f`(x)=[(2x+3)`(3x+5)-(3x+5)`(2x+3)]/(3x+5)²=(2(3x+5)-3*(2x+3))/(3x+5)²=(6x+10-6x-9)/(3x+5)²=1/(3x+5)²
4
f(x)=(x+3)/(x-1)
f`(x)=[(x+3)`*(x-1)-(x-1)`*(x+3)]/(x-1)²=(1(x-1)-1(x+3))/(x-1)²=
=(x-1-x-3)/(x-1)²=-4/(x-1)²