Does straight lines have slopes of tanget?

[Tanya Back]

Does straight lines have slopes of tangent?.. :confused: i had no clue when this question came on a test..so i just left it...do they?..i just thought maybe they didn't since they have no limit. Hope i get an answer for this question.

Tanya

[maverick280857]

A straight line has the equation

y = mx + c

here m is called its slope and c is the y-intercept. If you do not know, then this is a formula relating the y-coordinate of a point on the line to its x-coordinate (remember there must be a specific relationship between the x and y coordinates of a point if it moves on a well defined non-arbitrary curve...in this case the curve is a straight line).

A straight line does have a tangent also called its slope. The important thing is that the slope of a straight line is constant (unlike that of other curves which may change from point to point...draw a diagram of a circle to convince yourself that this is so). Secondly, only two parameters are required to fix a straight line:

1. Two points or
2. One point and the slope
3. Slope and y-intercept

The more general equation of a straight line in the cartesian plane is

ax + by + c = 0

but as you can see, it can be transformed into the form mentioned above using simple algebraic manipulations.

Cheers
Vivek

[Hurkyl]

Every line is its own tangent line at each of its points.

[HallsofIvy]

I think what you mean is this: the slope of a straight line is the tangent of the angle the line makes with the x-axis. That is true.

[Tanya Back]

Thank u guys!!!! I understand much better now..i wish i had asked this question before the test ..oh well.. anyways Thank u

Tanya