If $x - 2y = 4,$ the minimum value of $xy$ is

The necessary condition for a function to have a maximum or minimum value is:

If $x + y = 16$ and $x^2 + y^2$ is minimum,then the values of $x$ and $y$ are

Let $f: R \rightarrow R$ be a function defined by $f(x) = (x - 3)^{n_{1}}(x - 5)^{n_{2}}$,where $n_{1}, n_{2} \in N$. Which of the following is $\text{NOT}$ true?

If the function $f(x)=2 x^3-9 a x^2+12 a^2 x+1$,where $a > 0$,attains its local maximum and local minimum values at $p$ and $q$ respectively,such that $p^2=q$,then $f(3)$ is equal to:

Let $p(x)$ be a polynomial of degree $4$ having extrema at $x=1$ and $x=2$,and $\lim_{x \rightarrow 0} \left(1+\frac{p(x)}{x^2}\right) = 2$. Then the value of $p(2)$ is