Question

Find what straight lines are represented by the following equation and determine the angles between them.
$y^2-16=0$

Answer 1

$y^2-16=0$

Factorising the equation

$(y+4)(y-4)=0y+4=0,y=-4y=-4,y=4$

Slope of first line $m_1=0$

Slope of second line $m_2=0$

Angle between two straight lines

$\tan \theta =\left|\frac{m_1-m_2}{1+m_1{m}_2}\right|=\left|\frac{0-0}{1+0.0}\right|\tan \theta =\frac{0}{1}=0\Rightarrow \theta ={\tan }^{-1}\left(0\right)=0$