The smallest perimeter that a rectangle with area of 4 square units can have is ______ units.

(Answer in integer)

The initial value problem

$\rm \frac{dy}{dt}+2y=0, y(0)=1$

is solved numerically using the forward Euler’s method with a constant and positive time step of Δt. 

Let 𝑦_𝑛 represent the numerical solution obtained after 𝑛 steps. The condition |𝑦_n+1| ≤ |𝑦_n| is satisfied if and only if Δt does not exceed _____________.

(Answer in integer)

$$\,\,P\,\,\,\left( {0,3} \right),\,\,Q\,\,\,\left( {0.5,4} \right),\,\,$$ and $$\,\,R\,\,\,\left( {1,5} \right)\,\,\,$$ are three points on the curve defined by $$\,\,f\left( x \right),\,\,$$ Numerical integration is carried out using both Trapezoidal rule and Simpson's rule within limits $$x=0$$ and $$x=1$$ for the curve. The difference between the two results will be

The error in numerically computing the integral $$\,\int\limits_0^\pi {\left( {\sin \,x + \cos \,x} \right)dx\,\,\,} $$ using the trapezoidal rule with three intervals of equal length between $$0$$ and $$\pi $$ is _________.