 Hi, and welcome to the session. I am Deepika here. Let's discuss a question. If fx is equal to 3x square plus 15x plus 5, then the approximate value of f of 3.02 is a 46.66, b 57.66, c 67.66 and d 77.66. So let's start the solution. Given fx is equal to 3x square plus 15x plus 5 and let x is equal to and delta x, which is a small increment in x is equal to 0.02. Now we know that the corresponding increment in y is delta y, that is delta y is equal to f of x plus delta x minus fx. This implies f of x plus delta x is equal to f of x plus delta y. Now we have to find the value of f of 3.02, that is f of 3.02 is equal to f of x, that is 3x square plus 15x plus 5 plus delta y, that is dy by dx into delta x. And this is equal to 3x square plus 15x plus 5 plus dy by dx is our 6x plus 15 and delta x is 0.02. And this is equal to, now put the value of x here, 3, that is 3 into 3 square plus 15 into 3 plus 5. Plus 6 into 3 plus 15 into 0.02 and this is equal to 27 plus 45 plus 5 plus 18 plus 15 into 0.02 and this is equal to 77 plus 33 into 0.02 and this is equal to 77 plus 0.66 and therefore f of 3.02 is equal to 77.66. Hence option D is correct, that is D is the correct answer. I hope the question is clear to you, bye and take care.