Which of the following statements is $NOT$ correct for potash alum?

If $\int \frac{\sin x}{\cos x(1+\cos x)} d x=f(x)+c$,then $f(x)$ is equal to

The equation of the tangent at $(-4, -4)$ on the curve $x^2 = -4y$ is

$A$ rod of glass $(\mu = 1.5)$ with a square cross-section is bent into the shape shown in the figure. $A$ parallel beam of light falls on the plane flat surface $A$ as shown. If $d$ is the width of a side and $R$ is the radius of the inner circular arc, then for what maximum value of $\frac{d}{R}$ will light entering the glass slab through surface $A$ emerge from the glass through surface $B$?

Which of the following is not a peroxy acid?

Filiform apparatus is a characteristic feature of