)=(2,−11,−7) Given A×B=C We know that, Let A=(u1,u2,u3) and B=(v1,v2,v3) be any two vectors then its cross product is A×B:(u1,u2,u3)×(v1,v2,v3)=(u2v3−u3v2,u3v1−u1v3,u1v2−u2v1) Consider A×B=C A×B:(λ,1,−1)×(3,−2,4)=((1)(4)−(−1)(−2),(−1)(3)−(λ)(4),(λ)(−2)−(1)(3))=(2,−11,−7) ⇒(2,−3−4λ,−2λ−3)=(2,−11,−7) Vectors are equal. Their corresponding elements are equal. ⇒−2λ−3=−7 ⇒2λ+3=7 ⇒λ=2