Posted by **TP** on Thursday, February 19, 2009 at 1:21am.

I just had a test, and one question I tried heaps of times and I still couldn't answer. It was "Prove secèsinè + cosecè cosè = 2cosecè "

Can someone please tell me if proving this is possible at all? (But don't tell me how to solve it)

- Maths - Trig -
**Damon**, Thursday, February 19, 2009 at 4:30am
sin x/cos x + cos x/sin x =

(sin^2 x + cos^2 x)/(sin x cos x )=

1/(sin x cos x)

I do not see how that comes out to 2 cosec x

- Maths - Trig -
**Reiny**, Thursday, February 19, 2009 at 9:30am
Usually my first step in proving any trig identity is taking an arbitrary angle to see if it makes it true, say 45 degrees.

Picking up from Damon's first line, your equation is

tanx + cotx = 2/sinx

for x = 45 degrees

LS = 1+1 = 2

RS = 2/.707 which is not LS

so the equation is not an identity.

## Answer This Question

## Related Questions

- Maths - (tanÈ+cotÈ)(sinÈ+cosÈ)=secÈ+cosecÈ
- chemistry - This question I really don't get it. I tried tried tried to figure ...
- trig - Write the expression and evaluate. There is only one answer whIch should ...
- Calculus - Using l'hopitals rule, evaluate the following: Lim x-->infinity ...
- Question,drbob222,math - Drbob222, even if you just tell me that there is an ...
- writing - i just had a question. if i write down an essay a sort one can someone...
- English - I urgently need you to check these sentences on the present perfect. ...
- Geometry proving quadrilaterals - Proving quadrilaterals PLEASE PLEASE PLEASE ...
- trig - How do you solve for these identities: 1-sin^2è/cosè= cosè sin^4è-cos^4è=...
- Math - How do you solve this? I posted this question last night and someone ...

More Related Questions