Quantcast 3rd Year HS : Trigometric Identities. - XP Math - Forums
XP Math Home Sign Up FREE! | Sign In | Classroom Setup | Common Core Alignment PDF Version

Go Back   XP Math - Forums > Mathematics > Homework Help

Thread Tools Display Modes
Old 01-19-2009   #1
Posts: n/a
Default 3rd Year HS : Trigometric Identities.

Hello guys.

I'm really having difficulties in answering Trigometric identities

kindly help me with this.

This is the Fundamental Trigonometric Identities Chart that my teacher gave me.

and this the problem that I need to prove.


please explain them to me .

and can I ask for techniques or ways to answer this without difficulties?
Old 01-20-2009   #2

Join Date: Dec 2008
Posts: 249

1. 1 - sin/csc = cos/sec

Let's work on the left-hand side (LHS).

1 - sin/(1/sin) = cos/sec

1 - sin*sin = cos/sec

cos*cos = cos/sec

cos(1/sec) = cos/sec

cos/sec = cos/sec

2. 1/(sec*sec) = 1 - 1/(csc*csc)

Work on the RHS.

1/(sec*sec) = 1 - 1/((1/sin)(1/sin))

1/(sec*sec) = 1 - sin*sin

1/(sec*sec) = cos*cos

1/(sec*sec) = (1/sec)(1/sec)

1/(sec*sec) = 1/(sec*sec)
MAS1 is offline  

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -4. The time now is 11:30 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
XP Math