If vec A and vec B are two non-zero vect | vedclass

Name: PDF Generator App | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

$\sqrt{A^{2}+B^{2}+2 A B \cos 	heta}=\frac{1}{2} 	imes \sqrt{A^{2}+B^{2}-A B \cos 	heta}$

$4\left(A^{2}+B^{2}+2 A B \cos 	hetaight)=A^{2}+B^{

Vedclass · Accepted Answer

$cos^{-1}(-3/4)$

Vedclass · Answer

$\sqrt{A^{2}+B^{2}+2 A B \cos 	heta}=\frac{1}{2} 	imes \sqrt{A^{2}+B^{2}-A B \cos 	heta}$

$4\left(A^{2}+B^{2}+2 A B \cos 	hetaight)=A^{2}+B^{2}-2 A B \cos 	heta$

$3 A^{2}+3 B^{2}+10 A B \cos 	heta=0$

$12 \mathrm{B}^{2}+3 \mathrm{B}^{2}+20 \mathrm{B}^{2} \cos 	heta=0$

$20 \mathrm{B}^{2} \cos 	heta=-15 \mathrm{B}^{2}$

$\cos 	heta=-\frac{3}{4}$

$	heta=\cos ^{-1}\left(-\frac{3}{4}ight)$

If $\vec A$ and $\vec B$ are two non-zero vectors such that $\left| {\vec A + \vec B} \right| = \frac{{\left| {\vec A - \vec B} \right|}}{2}$ and $\left| {\vec A} \right| = 2\left| {\vec B} \right|$ then the angle between $\vec A$ and $\vec B$ is

Similar Questions

A body moves due East with velocity $20\, km/hour$ and then due North with velocity $15 \,km/hour$. The resultant velocity..........$km/hour$

Give the names of two methods for vector addition. Write the law of parallogram for vector addition.

Prove the associative law of vector addition.

There are two force vectors, one of $5\, N$ and other of $12\, N $ at what angle the two vectors be added to get resultant vector of $17\, N, 7\, N $ and $13 \,N$ respectively

Figure shows three vectors $p , q$ and $r$, where $C$ is the mid point of $A B$. Then, which of the following relation is correct?