Question

The set of value of $x$ for which the angle between the $\overrightarrow a = 2x²\hat i + 4x \hat j + \hat k$ and $\overrightarrow b =7\hat i-2\hat j + x\hat k$ is obtuse is :

• A. $(0,\frac{1}{2})$
• B. $(0,\frac{1}{3})$
• C. $(\frac{1}{2},\frac{1}{3})$
• D. (0,1)

Answer 1

Answer: (A)

$(0,\frac{1}{2})$

Answer 2

The correct option is (A):

$(0,\frac{1}{2})$