00:01
The given f of x that is equal to 3x q minus 2x square minus 20 and the condition which is given to us that this function has exactly 1 positive 0 and we need to find that point where this value will be 0.
00:20
Okay so first of all we will check that between which two integral values are 0 is lying.
00:27
So first of all we'll check at 1 so f of 1 it will be like 3 1 cube that will be 3 minus 2 multiplied with 1 square so that will be minus of 2 minus of 20 so it's like more 3 minus 2 that will be 1 1 minus 20 that will be minus 19 now let's check for f of 2 so at f of 2 that will be 3 multiplied with 2 cube so that will be 8 2 multiplied with 2 square so that will be 4 minus 20 so it's like 24 minus 8 minus so that will obviously be minus of 4.
01:05
It means that between 1 and 2 are 0 is not lying.
01:09
Now let's check for a third point that is f of 3.
01:12
So at f of 3, it will like 3 multiplied with 3 cube, so that will be 3 to the power 4, minus 2 multiplied with 3 squared, so 2 multiplied with 9 minus 20.
01:23
So it's like 3 to power 4, that is 801 minus 20.
01:29
So obviously that will be some positive value...