Solution 2.3:9a
From Förberedande kurs i matematik 1
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| - | A point lies on the   | + | A point lies on the ''x''-axis if it has ''y''-coordinate 0 and we therefore look for all the points on the curve <math>y=x^{2}-1</math> where <math>y=0</math>,  i.e. all points which satisfy the equation   | 
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| - | -axis if it has   | + | |
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| - | -coordinate   | + | |
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| - | and we therefore look for all the points on the curve   | + | |
| - | <math>y=x^  | + | |
| - | where   | + | |
| - | <math>y=0</math>,  i.e. all points which satisfy the equation   | + | |
| + | {{Displayed math||<math>0=x^{2}-1\,\textrm{.}</math>}}  | ||
| - | + | This equation has solutions <math>x=\pm 1</math>, which means that the points of intersection are <math>(-1,0)</math> and <math>(1,0)</math>.  | |
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| - | This equation has solutions  | + | |
| - | <math>x=\pm   | + | |
| - | <math>  | + | |
| - | and  | + | |
| - | <math>  | + | |
[[Image:2_3_9_a.gif|center]]  | [[Image:2_3_9_a.gif|center]]  | ||
Current revision
A point lies on the x-axis if it has y-coordinate 0 and we therefore look for all the points on the curve \displaystyle y=x^{2}-1 where \displaystyle y=0, i.e. all points which satisfy the equation
| \displaystyle 0=x^{2}-1\,\textrm{.} | 
This equation has solutions \displaystyle x=\pm 1, which means that the points of intersection are \displaystyle (-1,0) and \displaystyle (1,0).

