Question

The contentment obtained after eating x-units of a new dish at a trial function is given by the function $f(x)=x^{3}+6x^{2}+5x+3.$. If the marginal contentment is defined as the rate of change of f(x) with respect to the number of units consumed at an instant, then find the marginal contentment when three units of dish are consumed.

Find the solution of the differential equation ${\frac{d y}{d x}}=x^{3}e^{-2y}$.

Find : $\int{\frac{3\,x}{3\,x-1}}\,d x$

Write the value of $\stackrel{\rightarrow}{p}\$ for which the vectors $3\stackrel{\wedge}{i}+2\stackrel{\wedge}{j} +9\stackrel{\wedge}{k}$ and $\stackrel{\wedge}{i}-2p\stackrel{\wedge}{j} +3\stackrel{\wedge}{k}$ are parallel vectors.

If A is a 3 × 3 matrix, whose elements are given by $a_{i j}={\frac{1}{3}}|-3i+j\,|$ , then write the value of $a_{23}$.

Write the order of product matrix $\left(\begin{array}{l }1 \\ 2 \\ 3\end{array}\right)$ $\left(\begin{array}{l l l }2 & 3 & 4\end{array}\right)$

If A = $\left(\begin{array}{l l }cosα & -sinα \\ sinα & cosα\end{array}\right)$ , then for what value of a, A is an identity matrix ?