Interview
Trigonometry Gr 11 Identities Revision
- Course
- Mathematics
- Institution
- 11
Trigonometry Gr 11 Identities Revision
[Show more]
Seller
Follow
Content preview
REVISION: GRADE 11 TRIG IDENTITIES AND REDUCTION FORMULAEIdentities
sin A
tan A = cos A
sin2 A + cos2 A = 1
Hence
sin2 A = 1 − cos2 A
and
cos2 A = 1 − sin2 A
180° rule and negative angles
sin( 180° − A) = sin A cos( 180° − A) = − cos A tan( 180° − A) = − tan A
sin( 180° + A) = − sin A cos( 180° + A) = − cos A tan( 180° + A) = tan A
sin( 360° − A) = − sin A cos( 360° − A) = cos A tan( 360° − A) = − tan A
sin( − A) = − sin A cos( − A) = cos A tan( − A) = − tan A
90° rule
sin( 90° − A) = cos A
cos( 90° − A) = sin A
Special angles
We use our knowledge of the standard graphs for sin, cos and tan of values like 0°, 90°,
180° and 360°, and the special triangles for reductions that lead to 30°, 45° and 60°.
(90;1) (0;1) (360;1)
1
(45;1). 45° √2 2
(360;0) 30°
(360;0) (270;0) (0;0) 1 √3
(180;0) (90;0) (180;0)
45° 60°
-1 1 1
(270;-1) (180;-1)
1 1 √3
sin 0° = 0 sin 30° = sin 45° = sin 60° = sin 90° = 1 sin 180° = 0 sin 270 ° = −1 sin 360° = 0
2 √2 2
√3 1 1
cos 0° = 1 cos 30° = cos 45° = cos 60° = cos 90° = 0 cos 180° = −1 cos 270 ° = 0 cos 360° = 1
2 √2 2
1 √3 tan 90° is tan 270° is
tan 0° = 0 tan 30° = tan 45° = 1 tan 60° = tan 180° = 0 tan 360° = 0
√3 2 undefined undefined
1
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller kalebroodt. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R50,00. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
52355 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now