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The angle between two vectors vecaandvec...

The angle between two vectors `vecaandvecb` with magnitudes `sqrt3` and 4, respectively and `veca.vecb=2sqrt3` is

A

`(pi)/(6)`

B

`(pi)/(3)`

C

`(pi)/(2)`

D

`(5pi)/(2)`

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The correct Answer is:
To find the angle between the two vectors \(\vec{a}\) and \(\vec{b}\) given their magnitudes and dot product, we can follow these steps: ### Step 1: Write down the given information We know: - Magnitude of \(\vec{a} = |\vec{a}| = \sqrt{3}\) - Magnitude of \(\vec{b} = |\vec{b}| = 4\) - Dot product \(\vec{a} \cdot \vec{b} = 2\sqrt{3}\) ### Step 2: Use the formula for dot product The dot product of two vectors can be expressed as: \[ \vec{a} \cdot \vec{b} = |\vec{a}| \cdot |\vec{b}| \cdot \cos \theta \] where \(\theta\) is the angle between the vectors. ### Step 3: Substitute the known values into the formula Substituting the values we have: \[ 2\sqrt{3} = (\sqrt{3}) \cdot (4) \cdot \cos \theta \] ### Step 4: Simplify the equation Calculating the right side: \[ 2\sqrt{3} = 4\sqrt{3} \cdot \cos \theta \] Now, divide both sides by \(4\sqrt{3}\): \[ \cos \theta = \frac{2\sqrt{3}}{4\sqrt{3}} = \frac{2}{4} = \frac{1}{2} \] ### Step 5: Find the angle \(\theta\) We know that: \[ \cos \theta = \frac{1}{2} \] The angle \(\theta\) that satisfies this equation is: \[ \theta = \frac{\pi}{3} \text{ radians} \quad \text{(or 60 degrees)} \] ### Conclusion The angle between the two vectors \(\vec{a}\) and \(\vec{b}\) is \(\frac{\pi}{3}\). ---

To find the angle between the two vectors \(\vec{a}\) and \(\vec{b}\) given their magnitudes and dot product, we can follow these steps: ### Step 1: Write down the given information We know: - Magnitude of \(\vec{a} = |\vec{a}| = \sqrt{3}\) - Magnitude of \(\vec{b} = |\vec{b}| = 4\) - Dot product \(\vec{a} \cdot \vec{b} = 2\sqrt{3}\) ...
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