Comparing Gradient: Highest & Lowest, Vector/Scalar?

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songoku
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If, let say, I have 3 equation of lines:
Line 1: y = 3x + 10
Line 2: y = 0
Line 3: y = -4x

which line has the highest and lowest gradient?

Is gradient in equation of line vector quantity or scalar quantity?

Do we say gradient = 0 is higher than gradient = -4 or is gradient = -4 is higher than 0 because the gradient is only "directed" downwards?

Thanks
 
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Usually it would be regarded as a vector quantity, so that Line 1 has the highest gradient.
A term that is sometimes used for gradient as a scalar is 'steep'. We would say the Line 3 has the steepest gradient.

If it is an assignment question and you are not sure what the lecturer intended, I suggest you give both answers and explain why they are different.
 
The three equations are those of lines. The terminology we use in the US is "slope," as "gradient" is usually reserved to the discussion multivariate functions.
For example, if ##w = f(x, y, z)## is a function of three variables, the gradient of f, denoted ##\nabla f## can be written as ##\nabla f = \frac{\partial f}{\partial x} \textbf i + \frac{\partial f}{\partial y}\textbf j + \frac{\partial f}{\partial z} \textbf k##.

The slopes of the three lines are 3, 0, and -4, respectively. Although -4 < 0 < 3, the third line is the steepest.
 
andrewkirk said:
Usually it would be regarded as a vector quantity, so that Line 1 has the highest gradient.
A term that is sometimes used for gradient as a scalar is 'steep'. We would say the Line 3 has the steepest gradient.
Is there difference between "highest gradient" and "steepest gradient"?
If I want to find highest gradient, it is line 1 but if I want to find steepest gradient, it is line 3?

If it is an assignment question and you are not sure what the lecturer intended, I suggest you give both answers and explain why they are different.
I need to draw something related to gradient (slope) so I have to understand about this

Thanks