If ` veca and vecb` are unit vectors inclined to x-axis at angle ` 30^(@) and 120^(@)` then ` |veca +vecb|` equals

If veca and vecb are unit vectors inclined at an angle theta then prove that cos(theta/2) = 1/2|veca +vecb|

If veca and vecb are two unit vectors inclined at an angle pi//3 then { veca xx (vecb+veca xx vecb)} .vecb is equal to

If veca and vecb are two unit vectors inclined at an angle pi//3 then { veca xx (vecb+veca xx vecb)} .vecb is equal to

Let veca and vecb are unit vectors inclined at an angle alpha to each other , if |veca+vecb| lt 1 then

Let veca and vecb are unit vectors inclined at an angle alpha to each other , if |veca+vecb| lt 1 then

If veca and vecb are two unit vectors inclined at an angle pi/3 then { veca xx (vecb+veca xx vecb)} .vecb is equal to (a) -3/4 (b) 1/4 (c) 3/4 (d) 1/2

If veca and vecb are unit vectors inclined at an angle theta , then the value of |veca-vecb| is

If veca and vecb are unit vectors inclined at an angle theta , then the value of |veca-vecb| is

If veca and vecb are unit vectors inclined at an angle theta ,then prove that sin(theta/2)=1/2|veca-vecb|