Given vectors are →a=2^i+2^j+3^k,→b=−^i+2^j+^k and →c=3^i+^j
(→a+λ→b)=(2^i+2^j+3^k)+λ(−^i+2^j+^k)
(→a+λ→b=(2−λ)^i+(2+2λ)^j+(3+λ)^k
Since, (→a+λ→b) is perpedicular to →c.
Therefore, (→a+λ→b).→c=0
[(2−λ)^i+(2+2λ)^j+(3+λ)^k].(3^i+^j+0^k)=0
(2−λ).3+(2+2λ).1+(3+λ).0=0
6−3λ+2+2λ=0
8−λ=0
λ=8
Final answer:
Hence, λ=8