Find the angle the normal makes with the positive x–axis.

1. 3x – 2y – 1 = 0
2.5x + y – 12 = 0
3. 4x + 3y – 4 = 0
I cant Figure any of these out or how to do them..

2 answers

You should have learned that the slope of a line is equal to tanØ, where Ø is the angle that the line makes with the positive x-axis

for #1
slope of that line is 3/2
so tanØ = 3/2
Ø = tan^-1 (3/2)

my calculator gave me appr. 56.3°

do the others the same way
1. sqrt2x + sqrt2y + 36 = 0
2. Normal form: 2x/sqrt53 + 7y/sqrt53 - 4/sqrt53 = 0 Angle:74
3. 3x/srt13 + 2y/sqrt13 - 5/sqr13 = 0 Angle:34
4. 326
5. 11
6. 37