Find the points on y-a xi s whose perpendicular distance from the line `4x-3y-12=0` is `3.`

Explanation

Let the required point be P(0,alpha). It is given that the length of the perpendicular
from P(0,alpha) on `4x-3y-12=0 `is `3. `


Therefore,
`|4(0)−3alpha−12|/(sqrt(4^2+(−3)^2+3)`

`|3alpha+12|=25`

` |alpha+4|=5 `

`alpha+4=±5 `

`alpha=1,−9 `


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