Question

Are these identities true for 0º < A < 90º ? If not, for which values of A they are true?
a. sec² A − tan²A = 1 b. cosec²A − cot²A = 1

Answer 1

Answer:

I am in class 11 am going to explain it from that viewpoint.

The identities ,

sec²A-tan²A=1 and cosec²A-cot²A=1 ; are true for all real values of A.

So yes it is true for 0˚ < A < 90˚.

It is true for A∈R      [R=all real numbers]