Unit 2 Earth Materials Lab 2 3 Igneous Rock Identification Essay

761 Words Dec 9th, 2012 4 Pages
More important identities
You don't have to know all the identities off the top of your head. But these you should.
Defining relations for tangent, cotangent, secant, and cosecant in terms of sine and cosine.
|tan t = |sin t | |cot t = |1 |= |cos t |
| |[pic] | | |[pic] | |[pic] |
| |cos t | | |tan t | |sin t |
|sec t = |1 | |csc t = |1 | | |
| |[pic] | | |[pic] | | |
| |cos t | | |sin t | | |

The Pythagorean formula for sines and cosines. sin2 t + cos2 t = 1
Identities expressing trig functions in terms of
…show more content…
|[pic] |
| |1 + tan s tan t |
|tan 2t = |2 tan t |
| |[pic] |
| |1 – tan2 t |

Half-angle formulas sin t/2 = ±[pic]((1 – cos t) / 2) cos t/2 = ±[pic]((1 + cos t) / 2)
|tan t/2 = |sin t |= |1 – cos t |
|

Related Documents