∓

The plus sign (+) placed below the minus sign (−), as an inverse of ±.

∓ (English symbol name minus-plus sign)

1. (mathematics) Used after ± to indicate that when the first operation is 'plus', this one is 'minus', and vice versa.

   ${\displaystyle \cos(x\pm y)=\cos x\cos y\mp \sin x\sin y\iff {\big (}\cos(x+y)=\cos x\cos y-\sin x\sin y\wedge \cos(x-y)=\cos x\cos y+\sin x\sin y{\big )}}$

2. (chess) Advantage for black.
3. (astrology) A tredecile (3⁄10) aspect of 108°.

   Synonym: D³

• ±