Two vectors `vecA` and `vecB` have precisely equal magnitudes. For the magnitude of `vecA + vecB` to be larger than the magnitude of `vecA- vecB` by a factor n, what must be the angle between them ?

Explanation

`|vecA+vecB|=n|vecA-vecB|`
`2A "cos"(theta)/(2)=n2A "sin"(A=B)`
`:. "tan" (theta)/(2)=(1)/(2), (theta)/(2)= tan^(-1)((1)/(n)), theta= 2tan^(-1)((1)/(n))`