Which of the following animals possesses a four-chambered heart?

Which of the following has the highest dipole moment?

$\tan A + 2 \tan 2A + 4 \tan 4A + 8 \cot 8A = $

$A$ thermodynamic system is taken through the cycle $PQRS P$ process. The net work done by the system is ....... $J$. (Note: Assuming a standard $P-V$ diagram where $P$ is in $kPa$ and $V$ is in $m^3$,with vertices $P(1, 10)$,$Q(3, 10)$,$R(3, 20)$,$S(1, 20)$)

If $y(x)$ is the solution of the differential equation $(x + 2)\frac{dy}{dx} = x^2 + 4x - 9, x \ne -2$ and $y(0) = 0$,then $y(-4)$ is equal to

If $\frac{dy}{dx} + 2x \tan(x-y) = 1$,then $\sin(x-y)$ is equal to