Addition and Subtraction Formulas
Proof of the Sine angle sum/difference identity.
Trig Identities Cosine Addition and Subtraction
Proof of the Cosine angle sum/difference identity.
Trig Identities Tangent and using the identities
Proof of the Tangent angle sum/difference identity.
Trig Identities
The fundamental trig identities and some strategies for solving beginning general trigonometric identities.
Sum and Difference Identities for Sine
Use the sum and difference sine identity to determine function values.
Sum and Difference Identities for Cosine
Use the sum and difference cosine identity to determine function values.
Sum and Difference Identities for Tangent
Use the sum and difference tangent identity to determine function values.
Cosine addition identity example.
Check out our most popular games!
Fraction Concoction Game:
Master fractions in the lab: mix, add, and subtract beakers to create the perfect concoction!
Fact Family Game:
Complete fact families and master the link between addition & subtraction and multiplication & division.
Number Bond Garden:
Clear the board by matching number pairs that sum to ten in this garden-themed mental math puzzle.
Online Addition Subtraction Game:
Practice your addition and subtraction skills to help the penguin find its mummy.
Penguin Solitaire
Penguin Solitaire is a fun game that aims to move all cards to the foundations to build four full sequences. There are two versions here: Penguin (Tuxedo) and Penguin (Original).
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