Question

secant (square) 90-tan(square)90 is not equal to one ...why??? ​

Answer 1

We know that, sec²∅-tan²∅=1

Also, tan90° = Infinity or Not Defined

So tan²90° = Infinity or Not Defined

And, sec90°= Infinity or Not Defined

Therefore,

sec²90° - tan²90°

= Infinity or N.D. - Infinity or N.D.

= 0

Hope it helps...