Is #tan^2x -= sec^2x - 1# an identity?
2 Answers
Jan 9, 2018
True
Explanation:
Start with the well known pythagorean identity:
# sin^2x + cos^2x -= 1 #
This is readily derived directly from the definition of the basic trigonometric functions
Divide both side by
# sin^2x/cos^2x + cos^2x/cos^2x -= 1/cos^2x #
# :. tan^2x + 1 -= sec^2x #
# :. tan^2x -= sec^2x - 1#
Confirming that the result is an identity.
Jan 9, 2018
Yes,
Explanation:
We start from
Then divide everything by
Rearrange to find