At what angle two vectors of magnitudes vecA +vecBand A - B act, so that their resultant is sqrt(3A^2 + B^2)?

At what angle two vectors of magnitudes vecA +vecBand A - B act, so th

1.	At what angle two vectors of magnitudes vecA +vecBand A - B act, so that their resultant is sqrt(3A^2 + B^2)?
Answer» `30^@` `45^@` `60^@` `90^@` ANSWER :C