Straight Lines Class 11

Straight Lines class 11 – If \(\theta\) is the inclination of a line l, then the slope of a line is given by tan θ. It is denoted by ‘m’. The slope of a line is not defined if it has 90 degree inclination. Thus, \(m \;=\; tan \theta , \;θ \neq 90\). Also, the slope of x axis is 0 and not defined for y axis. The acute angle between two lines \(L_{1}\;and\;L_{2}\) with slopes \(m_{1}\;and\;m_{2}\) is given by

\(tan\theta =\left | \frac{m_{2}-m_{1}}{1+m_{1}m_{2}} \right |\)

The obtuse angle can be found by using \(\phi =180-\theta\). 3 points A,B, and C are said to be collinear if slope of AB and BC are equal. The point (x, y) lies on the line if its coordinates satisfy the equation: \(y–y_{0} = m(x–x_{0})\) where m = slope through the fixed point \(\left ( x_{0} ,y_{0}\right )\).

The equation of line whose intercept on x axis is ‘a’ and intercept on y axis is ‘b’ is given by: \(\frac{x}{a}+\frac{y}{b}=1\)

The perpendicular distance of a line Ax + By+ C = 0 from a point \(\left ( x_{1},y_{1}\right )\) is given by:

\(d=\frac{\left | Ax_{1}+By_{1}+c \right |}{\sqrt{A^{2}+B^{2}}}\)

The Distance between two parallel lines \(Ax+By+C_{1}=0\) and \(Ax+By+C_{1}=0\) is given by:

\(d=\frac{\left | C_{1}-C_{2} \right |}{\sqrt{A^{2}+B^{2}}}\)

Straight Lines class 11 Examples

Straight Lines Class 11
Straight Lines Class 11
Straight Lines Class 11
Straight Lines Class 11
Straight Lines Class 11
Straight Lines Class 11
Straight Lines Class 11
Straight Lines Class 11
Straight Lines Class 11


Practise This Question

If p(qr) is false, then the truth values of p,q,r are respectively