Archive for the ‘trigonometry’ Category

h1

Special Limit for Cosine

February 23, 2010

Proof:

\lim_{h\to 0} \frac{\cos(h) - 1}{h} = 0

Read the rest of this entry ?

Posted in calculus, Limits, proof, trigonometry | Tagged , , , , , , | Leave a Comment »

h1

Definition: cis(θ)

February 22, 2010

Definition:

\mathrm{cis}(\theta) =\cos(\theta) + i\cdot\sin(\theta)

Posted in complex numbers, definition, trigonometry | Tagged , , , | Leave a Comment »

h1

Modified Pythagorean Identity: Cotangent

February 22, 2010

Proof:

1 + \cot^2(\theta) = \csc^2(\theta)

Read the rest of this entry ?

Posted in proof, trigonometry | Tagged , , , , | Leave a Comment »

h1

Cosine: Difference of Angles

February 22, 2010

Proof:

\cos(\alpha - \beta) = \cos(\alpha)\cos(\beta) + \sin(\beta)\sin(\alpha)

Read the rest of this entry ?

Posted in proof, trigonometry | Tagged , , , , | Leave a Comment »

h1

Cosine: Sum of Angles

February 22, 2010

Proof:

\cos(\alpha + \beta) = \cos(\alpha)\cos(\beta) - \sin(\beta)\sin(\alpha)

Read the rest of this entry ?

Posted in proof, trigonometry | Tagged , , , , | Leave a Comment »

h1

Sine: Difference of Angles

February 21, 2010

Proof:

\sin(\alpha - \beta) = \sin(\alpha)\cos(\beta) - \sin(\beta)\cos(\alpha)

Read the rest of this entry ?

Posted in proof, trigonometry | Tagged , , , , | Leave a Comment »

h1

Modified Pythagorean Identity: Tangent

February 21, 2010

Proof:

\tan^2(\theta) + 1 = \sec^2(\theta)

Read the rest of this entry ?

Posted in proof, trigonometry | Tagged , , , , , | 2 Comments »

Follow

Get every new post delivered to your Inbox.