The angle between the lines 2x=3y=−z and 6x=−y=−4z , is

The given lines may be written as x1/2=y1/3=z−1 and x1/6=y−1=z−1/4 Direction ratios of two lines are 12,13,−1 and 16,−1,−14Angle between two lines are given by cosθ=a1a2+b1b2+c1c2a1 2+b1 2+c1 2a2 2+b2 2+c2 2∴cosθ=12×16+13×(−1)+(−14)×(−1)14+19+1136+1+116=0⇒θ=900