Angle Of inclination linear function (1 Viewer)

[mtsmahia]

Hi guys.

Theres this Q which im stuck on...help will be appreciated..

The Q is , Find the angle of inclination of the line K (5x+3y-10=0) to the positive x-axis.

I know the gradient is = tan theta...but the gradient is negative, so i get a negative angle... ie -59

But the answer says 121 .. .

any idea how?

 

[addikaye03]

Hi guys.

Theres this Q which im stuck on...help will be appreciated..

The Q is , Find the angle of inclination of the line K (5x+3y-10=0) to the positive x-axis.

I know the gradient is = tan theta...but the gradient is negative, so i get a negative angle... ie -59

But the answer says 121 .. .

any idea how?

Think about it dude, if you got a negative gradient then its sloping downwards from left to right. If you found this angle (@) to be 59 degrees. Then the value w.r.t the positive x axis would be 180-@ ( Angle of a Straight Line, Coordinate Geometry Rule)

So Angle =180-@
=180-59
=121 degrees

 

[mtsmahia]

Think about it dude, if you got a negative gradient then its sloping downwards from left to right. If you found this angle (@) to be 59 degrees. Then the value w.r.t the positive x axis would be 180-@ ( Angle of a Straight Line, Coordinate Geometry Rule)

So Angle =180-@
=180-59
=121 degrees

ok...so do we just disregard the fact that angle -59 is negative, and just take it as positive 59. Then we subtract it from 180?

 

[shady145]

ur just using the acute angle, which is taken as a positive