00:01
First, we need to find the derivative of this function.
00:08
So, the derivative equals 2 .3 times 3 times x to a power of 3 minus 1, plus 2 times x to the power 2 minus 1, time minus 12, x to a power of 1 minus 1.
00:29
And the derivative of a constant equals 0.
00:35
We can rewrite this expression as 2x squared plus 2x minus 2.
00:47
For part a, we want to find an x, which is derivative equals to minus 2.
00:59
We just substitute the derivative with its expression, and which gives us 2x squared, plus 2x equals 0, and matrix 2x times x plus 1 equals 0.
01:26
And it gives us 2 values, x equals 0 or x equals minus 1.
01:38
For part b, we want to find the point that which is derivative equals 0...