Which of the following is the strongest conjugate base?

If $[x]$ denotes the greatest integer not exceeding $x$ and if the function $f$ defined by $f(x)= \begin{cases} \frac{a+2 \cos x}{x^2} & , x < 0 \\ b \tan \frac{\pi}{[x+4]} & , x \geq 0 \end{cases}$ is continuous at $x=0$,then the ordered pair $(a, b)$ is equal to

Which of the following statements is incorrect?

The potential energy of a particle of mass $m$ is given by $U(x) = \begin{cases} E_0; & 0 \le x \le 1 \\ 0; & x > 1 \end{cases}$. $\lambda_1$ and $\lambda_2$ are the de-Broglie wavelengths for $0 \le x \le 1$ and $x > 1$ respectively. If the total energy of the particle is $2E_0$,the ratio $\frac{\lambda_1}{\lambda_2}$ will be

The equation of the latus rectum of the parabola ${x^2} + 4x + 2y = 0$ is

Which of the following is an accessory whorl of a flower?