
(i) Find the rate of growth of the plant with respect to the number of days exposed to the sunlight.
(ii) Does the rate of growth of the plant increase or decrease in the first three days?
What will be the height of the plant after 2 days?

(i) Find the rate of growth of the plant with respect to the number of days exposed to the sunlight.
(ii) Does the rate of growth of the plant increase or decrease in the first three days?
What will be the height of the plant after 2 days?
(i) The rate of growth of the plant with respect to the number of days exposed to sunlight is given by $\frac{d y}{d x}=4-x$
(ii) Let rate of growth be represented by the function $g(x)=\frac{d y}{d x}$
Now, $g^{\prime}(x)=\frac{d}{d x}\left(\frac{d y}{d x}\right)=-1<0$
$\Rightarrow g(x)$ decreases.
So the rate of growth of the plant decreases for the first three days.
Height of the plant after 2 days is $y=4 \times 2-\frac{1}{2}(2)^2=6 \mathrm{~cm}$.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Based on the above information, answer the following questions.


(i) Find the rate of growth of the plant with respect to sunlight.
(ii) What is the number of days it will take for the plant to grow to the maximum height?
(iii) Verify that height of the plant is maximum after four days by second derivative test and find the maximum height of plant.
OR
What will be the height of the plant after 2 days?
