There are trignometrical equations that are nonstandard in aspect in that the equation may contain dissimilar terms, say algebric as well as trignometric expressions, or three may be only one equation in more than unknowns. In such cases we make use of the extreme values of trignometric functions or algebric functions. In particular `|sinx| le 1, |cos x| le 1`, and maximum/minimaof quadratic expressions are widely made use of
The equation `sin(pi/6)=x^(2)-6x+10` holds for