Q3 of 112 Page 163

Find the equation of a straight line whose

(i) slope is –3 and y–intercept is 4. (ii) angle of inclination is 60° and y–intercept is 3.

The equation of the straight line with the given slope (m) and y –intercept ‘c’ is given the slope–intercept form


i.e. y = mx + c


(i) Here given slope = –3 (m) and y intercept = 4 (c)


So the required equation is


y = –3x + 4


⇒ 3x + y–4 = 0


(ii) Given angle of inclination = 60° and y intercept = 3 (c)


Here slope of the line (m) = tan θ = tan 60° = √3


The required equation is


y = mx + c


⇒ y = √3x + 3


⇒ √3x –y + 3 = 0


More from this chapter

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1

Write the equations of the straight lines parallel to x- axis which are at a distance of 5 units from the x–axis.

 2

Find the equations of the straight lines parallel to the coordinate axes and passing through the point (–5,–2).

 4

Find the equation of the line intersecting the y- axis at a distance of 3 units above the origin and tan , where θ is the angle of inclination.

 5

Find the slope and y–intercept of the line whose equation is

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