The two questions both utilise a mix of trigonometry and factor theorem (of which an important concept is the idea that, and product that is zero is made of at least one factor that is zero. As such, we can simply solve for the values of x that give us factors that equal to zero.

Another important concept is that of the trigonometric range, which is applied here to ensure that we include all possible but not excessive values.

In part 2, a tricky component that is not entirely intuitive BUT conceptually important is to exclude values that make the expression undefined; since cot can be simplified as cos/sin, the expression is undefined whenever the denominator is zero i.e. sin4x = 0 which is a consideration you should include in your delivery of the final answer (though in this case it is not crucial to obtaining them)