Lösung 4.1:7b
Aus Online Mathematik Brückenkurs 1
(Unterschied zwischen Versionen)
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- | The equation is almost in the standard form for a circle; all that is needed is for us to collect together the | + | The equation is almost in the standard form for a circle; all that is needed is for us to collect together the ''y''²- and ''y''-terms into a quadratic term by completing the square |
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- | -terms into a quadratic term by completing the square | + | |
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+ | {{Displayed math||<math>y^2 + 4y = (y+2)^2 - 2^2\,\textrm{.}</math>}} | ||
After rewriting, the equation is | After rewriting, the equation is | ||
+ | {{Displayed math||<math>x^2 + (y+2)^2 = 4</math>}} | ||
- | <math> | + | and we see that the equation describes a circle having its centre at (0,-2) and radius <math>\sqrt{4}=2\,</math>. |
- | and we see that the equation describes a circle having its centre at | ||
- | <math>\left( 0 \right.,\left. -2 \right)</math> | ||
- | and radius | ||
- | <math>\sqrt{4}=2</math>. | ||
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- | {{NAVCONTENT_START}} | ||
<center> [[Image:4_1_7_b.gif]] </center> | <center> [[Image:4_1_7_b.gif]] </center> | ||
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- | {{NAVCONTENT_STOP}} |
Version vom 11:23, 8. Okt. 2008
The equation is almost in the standard form for a circle; all that is needed is for us to collect together the y²- and y-terms into a quadratic term by completing the square
After rewriting, the equation is
and we see that the equation describes a circle having its centre at (0,-2) and radius \displaystyle \sqrt{4}=2\,.