A Trig Proof

1. May 4, 2004

Alethia

Yes it is me again. :D Now with a trig problem XD

I was doing some problems on my homework in math, Trigonometry and I had problems proving this proof:

1+ cos Ө = csc Ө + cot Ө

I've worked it out until I simplified the right side to:

sin Ө
-----
1+ cos Ө

And then I realized that was the half identity of tangent. I can;t make the connnection further to make the proof true. Please help!! Have I simplified it wrong?

edit: the Ө is supposed to represent theta... but it keeps showing up like a square.. but you know what I mean. :D

2. May 4, 2004

Parth Dave

isnt csc = 1/sin and cot = cos/sin?

if that is so than the RS:
1/sin + cos/sin
(1+cos)/sin

(forgive me for not putting in thetas)

3. May 4, 2004

Alethia

Yeah that is what I got, but it's not eqaul to the left side, which is what I am supposed to do.

4. May 4, 2004

Hurkyl

Staff Emeritus
Do you believe the identity is correct?

5. May 5, 2004

Alethia

See that's why I am confused. I've checked my work about a million times (maybe 5 or so times :D) and I keep coming up with the same solution. I checked the answer in the book and it says that the proof is true... so either I'm doing something wrong or it's an error in the book. :1

6. May 5, 2004

Integral

Staff Emeritus
There must be a misprint, I did a quick calculation to show that they are equal at some point but certianly not in general
x..............1+cos(x)...........csc(x)+cot(x)
0.1.........1.995004165........19.98333055
0.2.........1.980066578.........9.966644423
0.3.........1.955336489.........6.616591506
0.4.........1.921060994.........4.933154876
0.5.........1.877582562.........3.916317365
0.6.........1.825335615.........3.232728144
0.7.........1.764842187.........2.739512159
0.8.........1.696706709.........2.36522242
0.9.........1.621609968.........2.070157361
1............1.540302306.........1.830487722
1.1.........1.453596121.........1.631041424
1.2.........1.362357754.........1.461695947
1.3.........1.267498829.........1.315435692
1.4.........1.169967143.........1.187241832
1.5.........1.070737202.........1.073426149
1.6.........0.970800478.........0.971214601

Last edited: May 5, 2004