Consider a line $\vec r= (\hat i + 4\hat j) +λ(2\hat i − 2\hat j + 3\hat k)$, then which of the following statements are correct? (A) it passes through point (9, -4, 12) Choose the correct answer from the options given below: |
(A), (C) and (D) only (B) and (C) only (A) and (C) only (B) and (D) only |
(A), (C) and (D) only |
The correct answer is Option (1) → (A), (C) and (D) only $\vec r=(1\,\hat i+4\,\hat j)+\lambda(2\,\hat i-2\,\hat j+3\,\hat k)$ Point on line (put $\lambda=0$): $(1,4,0)$ Direction ratios: $(2,-2,3)$ Direction cosines: $\ell=\frac{2}{\sqrt{17}},\; m=\frac{-2}{\sqrt{17}},\; n=\frac{3}{\sqrt{17}}$ Cartesian equation: $\frac{x-1}{2}=\frac{y-4}{-2}=\frac{z-0}{3}$ Checking options: (A) $(9,-4,12)$ on line → true (B) $(1,4,-1)$ not on line → false (C) direction cosines correct → true (D) Cartesian form correct → true Correct statements: (A), (C) and (D) |