Changes between Version 3 and Version 4 of u/johannjc/scratchpad13
- Timestamp:
- 03/11/16 13:54:34 (9 years ago)
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u/johannjc/scratchpad13
v3 v4 149 149 $\phi = \sin^{-1} \left ( -x / 2 \right )$ 150 150 151 152 [[Image(Screen Shot 2016-03-10 at 1.05.26 PM.png, width=400​)]] 153 154 [[Image(Screen Shot 2016-03-10 at 1.37.13 PM.png,width=400)]] 155 156 [[Image(Screen Shot 2016-03-10 at 1.48.34 PM.png,width=400​)]] 157 158 [[Image(Screen Shot 2016-03-10 at 2.01.55 PM.png​,width=400)]] 159 151 160 == Arbitrary direction == 152 161 … … 165 174 $\sin{\phi} = 1 \rightarrow e = \sqrt{1 - (1 + x)^2(1-x^2-2x)} = \sqrt{1 - ( (1 + 2x + x^2)(1 - x^2 - 2x))} = \sqrt{1 - (1 - x^2 - 2x + 2x - 2x^3 - 4x^2 + x^2 - x^4 - 2x^3)} = \sqrt{1-(1 - 4x^3 - 4x^2 - x^4 )} = \sqrt{4x^2+4x^3+x^4} = 2x+x^2$ 166 175 167