Which of the following plant groups possesses spores and embryos but is seedless and lacks vascular tissues?

Considering only the principal values of the inverse trigonometric functions,the value of $\tan \left(\sin ^{-1}\left(\frac{3}{5}\right)-2 \cos ^{-1}\left(\frac{2}{\sqrt{5}}\right)\right)$ is:

If the difference between the roots of the equations $x^2+ax+b=0$ and $x^2+bx+a=0$ is the same,and $a \neq b$,then:

$\int_0^{2 \pi} \sin^6 x \cos^5 x \, dx$ is equal to

The molar heat capacity of water at constant pressure is $75 \ J \ K^{-1} \ mol^{-1}$. When $1 \ kJ$ of heat is supplied to $100 \ g$ of water,which is free to expand,the increase in temperature of water is ............... $K$.

The rate of disintegration of a fixed quantity of a radioactive element can be increased by