Find the acute angle between the straight lines y = x and y = √3x

  • A 15°
  • B 30°
  • C 45°
  • D 60°
jamb 2009mathematics

The correct answer is A. 15°

y = x, Gradient (m

) = 1

y = √3x gradient (m

) = √3

\(tan\theta = \frac{m_2 - m_1}{1+m_2 m_1}\\

tan\theta = \frac{\sqrt{3}-1}{1+\sqrt{3}\times 1}\\

=\frac{1.73 -1 }{1+1.73}=

\frac{0.73}{2.73}=0.268\)

θ = Tan(0.268)= 15

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