The acute angle between two lines →r=2^i−5^j+^k+α(3^i+2^j+6^k) and →r=7^i−6^j+^k+β(^i+2^j+2^k) is
cosθ=(3^i+2^j+6^k).(^i+2^j+^2k)∣∣3^i+2^j+6^k∣∣.∣∣^i+2^j+2^k∣∣=3+4+127×3=1921θ=cos−1(1921)
Find the angle between the following pairs of lines :
r=2^i−5^j+^k+λ(3^i+2^j+6^k) and r=7^i−6^k+μ(^i+2^j+2^k)
r=3^i+^j−2^k+λ(^i−^j−2^k) and r=2^i−^j−56^k+μ(3^i−5^j−4^k)