There are
many functions which are not one-one, onto or both and
hence we can not talk of their inverses In Class XI, we
studied that trigonometric functions are not one-one and
onto over their natural domains and ranges and hence their
inverses do not exist In this chapter, we shall study about
the restrictions on domains and ranges of trigonometric
functions which ensure the existence of their inverses and
observe their behaviour through graphical representations Besides, some elementary properties will also be discussed