I have a trig identity proving question:

(1 - sin(x))/(1 + sin(x)) = tan(x) + 1/cos(x)

by multiplying 1 - sin(x) on left side doesn't seems work.

Anyone can help. Thanks in advanced.

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- March 3rd 2013, 06:24 AMellicottidentity proving with two terms in denominator
I have a trig identity proving question:

(1 - sin(x))/(1 + sin(x)) = tan(x) + 1/cos(x)

by multiplying 1 - sin(x) on left side doesn't seems work.

Anyone can help. Thanks in advanced. - March 3rd 2013, 07:02 AMSorobanRe: identity proving with two terms in denominator
Hello, ellicott!

Are there typos?

The statement is not true.

Quote:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

I found this identity . . .

. . . . . .

Therefore: .

- March 3rd 2013, 08:01 AMellicottRe: identity proving with two terms in denominator
Thanks Soroban for correction of my typo. In general, what is the method to test true identity? Do you have to use a particular angle such as pi/6?

appreciate your helps,