Find the intervals in which the following function are increasing or decreasing. `f(x)=10-6x-2x^2` `f(x)=x^2+2x-5` `f(x)=6-9x-x^2` `f(x)=2x^3-12 x^2+18 x+15` `f(x)=5+36 x+3x^2-2x^3` `f(x)=8+36 x+3x^2-2x^3` `f(x)=5x^3-15 x^2-120 x+3` `f(x)=x^3-6x^2-36 x+2` `f(x)=2x^3-15 x^2+36 x+1` `f(x)=2x^3+9x^2+20` `f(x)=2x^3-9x^2+12 x-5` `f(x)=6+12 x+3x^2-2x^3` `f(x)=2x^3-24 x+107` `f(x)=-2x^3-9x^2-12 x+1` `f(x)=(x-1)(x-2)^2` `f(x)=x^3-12 x^2+36 x+17` `f(x)=2x^3-24+7` `f(x)=3/(10)x^4-4/5x^3-3x^2+(36)/5x+11` `f(x)=x^4-4x` `f(x)=(x^4)/4+2/3x^3-5/2x^2-6x+7` `f(x)=x^4-4x^3+4x^2+15` `f(x)=5x^(3/2)-3x^(5/2),x >0` `f(x)==x^8+6x^2` `f(x)==x^3-6x^2+9x+15` `f(x)={x(x-2)}^2` `f(x)=3x^4-4x^3-12 x^2+5` `f(x)=3/2x^4-4x^3-45 x^2+51` `f(x)=log(2+x)-(2x)/(2+x),xR`