1.

The acute angle which the perpendicular from the origin on the line 7x –3y = 4 makes with the x-axis is:(a) zero (b) positive but not \(\frac{\pi}{4}\)(c) negative (d) \(\frac{\pi}{4}\)

Answer»

(c) negative

As the line from the origin is perpendicular to the line 

7x – 3y = 4, so its slope = \(\frac{-1}{\text{slope of }\,7x-3y=4}\)

Slope of 7x – 3y – 4 = \(\frac{7}{3}\)

∴ Slope of line from origin = \(\frac{-1}{+\frac{7}{3}}\) = \(\frac{-3}{7}\)

∴ tan θ = \(\frac{-3}{7}\), where θ is the angle the line makes with the +ve direction of x-axis

⇒ θ = tan-1 \(\big(\frac{-3}{7}\big)\) = - tan-1 \(\big(\frac{3}{7}\big)\)



Discussion

No Comment Found

Related InterviewSolutions