Verify that each equation is an identity?
(sec a - tan a)(sec a + tan a) = 1
(sec a - tan a)(sec a + tan a) = 1
1 Answer
Nov 29, 2016
Multiply out the brackets and then apply the Pythagorean Identity
Explanation:
Left Side = (SecA - TanA)(SecA + TanA)
=
Notice that
So Left Side =
Now apply the Pythagorean Identity
Left Side =
Left Side = 1
Left Side = Right Side [Q.E.D.]