Find the intervals in which the function `f(x)=2x^3+9x^2+12 x+20` is (i) increasing (ii) decreasing

Find the intervals in which the function f(x)=2x^(3)+9x^(2)+12x+20 is (i) increasing (ii) decreasing

Find the intervals in which the function f(x)=2x^(3) + 9x^2 + 12x + 20 is increasing

Find the intervals in which the function f(x) = 2x^3 + 9x^2 + 12x + 20 is increasing and decreasing.

Find the intervals in which the function f(x) = 2x^(3)-15x^(2)+36x + 6 is (i) increasing, (ii) decreasing.

Find the intervals in which the function f(x) = 2x^(3)-15x^(2)+36x + 6 is (i) increasing, (ii) decreasing.

Find the intervals in which the function f(x)=2x^3+9x^2+12 x+20 is increasing and decreasing.

The interval in which the function f(x)=2x^(3)-9x^(2)+12x-15 is increasing, is :