Find the value of λ which will make the vectors →a,→b and →c coplanar, where →a=2^i−^j+^k,→b=^i+2^j−3^k and →c=3^i−λ^j+5^k .
¯a,¯b,¯care coplanar⇒∣∣ ∣∣2−1112−33−λ5∣∣ ∣∣=0 ⇒2(10−3λ)+1(5+9)+1(−λ−6)=0⇒−7λ=−28⇒λ=4