The function f (x) = strictly increases on
At (0, 0) the curve
Hence an increasing function.
Hence an increasing function.
Let f (x) = then f (x) is strictly decreasing in
Hence an increasing function.
Hence decreasing function.
f (x) = – 4x
f'(x) = 4(x3) - 4 = 4(x 3- 1) = 4 {(x2) + x + 1)} (x-1)
= f ‘(x) > 0,if,(x - 1) > 0,
and f ‘(x) <0, if (x -1 ) < 0.
So,f is decreasing on ( - ,1]
and f is increasing on [1,)