Question

Find the slope of the line whose inclination is:

i) ${30}^{\circ }$

ii) ${120}^{\circ }$

iii) $\frac{2\pi }{3}$

iv) $\frac{3\pi }{4}$

Answer 1

Slope of the line is

$m=tan\theta$

$\left(i\right)\theta ={30}^{\circ }$

$m=tan{30}^{\circ }$

$=\frac{1}{\sqrt{3}}$

$\left(ii\right)\theta ={120}^{\circ }$

$m=tan{120}^{\circ }$ value in negative

$\theta =\frac{2\pi }{3}=\frac{2\times 180}{3}=120$ same previous

$\theta =\frac{3\pi }{4}=\frac{2\times 180}{4}=130$ value in negative

so answer is $\theta ={30}^{\circ }$