find the angle for the line

3x-15y+7

do i divid them all by -15 so that i get y alone?

-0.2x+y-0.46

y=-0.2x-0.46

this seems wrong somehow

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- Sep 29th 2007, 08:11 AMJBswefind the angle
find the angle for the line

3x-15y+7

do i divid them all by -15 so that i get y alone?

-0.2x+y-0.46

y=-0.2x-0.46

this seems wrong somehow - Sep 29th 2007, 08:36 AMred_dog
The line has an equation, not an expression.

$\displaystyle 3x-15y+7=0\Rightarrow y=\frac{1}{5}x+\frac{7}{15}$.

The slope is $\displaystyle m=\frac{1}{5}$.

On the other hand, the slope is the tangent of the angle between the line and the positive x-axis.

So, $\displaystyle m=\tan\alpha=\frac{1}{5}\Rightarrow\alpha=\arctan\ frac{1}{5}$.