00:01
Hello, we have a given equation of the curve that is x cube plus 3 x y square plus y cube is equal to 1.
00:10
Now we have a given formula for power rule that is d by dx x to the power n is equal to n multiplied by x to the power n minus 1 and also chain rule we have that is d by dx of f of g of x.
00:44
So this is equal to f dash g of x multiplied by g dash x and also the formula the product rule product rule which is given as d by dx of u multiplied by v where u and v is a function of x.
01:13
Now we have u multiplied by dv by dx and plus of v multiplied by dy dx.
01:23
Now for the implicit differentiation we can differentiate the given equation of the curve with respect to dx.
01:30
So we get here d by dx of the equation of the curve that is x cube plus 3 x y square plus y cube is equal to 1 that is differentiating 1 with respect to x as well.
01:49
So here we have d by dx of 1.
01:57
Now using these three formula so we get here d by dx of x cube which is equal to 3 x square and plus of now differentiating this by using the product rule we have 3 in the bracket that is x multiplied by 2 y multiplied by dy by dx and plus of y square multiplied by dx by dx plus of 3 y square multiplied by dy by dx is equal to 0 that is dy by dx at the point x naught comma y naught should be equal to 0.
02:45
So after putting the value here x naught and y naught we got that is x naught square plus y naught square and here minus which is divided by y naught square plus 2 x naught y naught is equal to 0.
03:06
So here we get that is x naught square plus y naught square is equal to 0.
03:12
Now from here we can see that that is x naught and y naught both are equal to 0.
03:18
We have but we can say x naught is equal to 0 and y naught is equal to 0 but at the 0 comma 0 is not the curve there is no horizontal tangent.
03:30
So from there we can say there is no horizontal tangent...