Establish each identity below.

(1) 9 sec^2 (x) - 5 tan^2 (x) = 5 + 4 sec^2 (x)

(2) cos(x)/[1 + sin(x)] + [1 + sin(x)]/cos(x) = 2 sec (x)

Printable View

- August 23rd 2008, 01:47 PMmagentaritaTrigonometric Identities
Establish each identity below.

(1) 9 sec^2 (x) - 5 tan^2 (x) = 5 + 4 sec^2 (x)

(2) cos(x)/[1 + sin(x)] + [1 + sin(x)]/cos(x) = 2 sec (x) - August 23rd 2008, 01:53 PMo_O
#1:

Note that . So substitute it in and simplify.

#2:

Combine into a single fraction:

Expand the numerator and simplify.

Post back if you have any troubles! - August 23rd 2008, 03:26 PMmagentaritaWhere???
- August 23rd 2008, 04:08 PMskeeterQuote:

What in the question indicated that you needed to make cosx/cosx

on the left side and 1 + sinx/1 + sinx on the right side?

- August 23rd 2008, 05:51 PMmagentaritaI see..
- August 23rd 2008, 06:52 PMo_O
An analogy:

- August 24th 2008, 02:48 PMmagentaritaGreat...
Great analogy!

Thanks