Asked by dennyelle
Explain why some trigonometric identities have restrictions or non-permissible
values. What are the restrictions for each of the reciprocal trigonometric ratios?
help
values. What are the restrictions for each of the reciprocal trigonometric ratios?
help
Answers
Answered by
mathhelper
If a trig function has a value of zero for a given angles, then clearly its
reciprocal will be undefined.
e.g. cos 90° = 0
then sec 90 = 1/0 which is undefined
e.g. tan 180° = 0, so cot 180° will be undefined.
So, whenever the graph of a trig function crosses the x-axis, that is,
when its value is zero, then its reciprocal function will be undefined for
that value of x
reciprocal will be undefined.
e.g. cos 90° = 0
then sec 90 = 1/0 which is undefined
e.g. tan 180° = 0, so cot 180° will be undefined.
So, whenever the graph of a trig function crosses the x-axis, that is,
when its value is zero, then its reciprocal function will be undefined for
that value of x
Answered by
dennyelle
thank you so much!