ঘন বিষয়ক সূত্র
- (a + b)3 = a3 + 3a2b + 3ab2 + b3 = a3 + b3 + 3ab (a + b)
- (a – b)3 = a3– 3a2b + 3ab2 – b3 = a3 – b3– 3ab (a – b)
- a3 + b3 = (a + b)(a2 – ab + b2) = (a + b)3– 3ab (a + b)
- a3– b3 = (a – b) (a2 + ab + b2) = (a – b)3 + 3ab (a – b)
- a3 + b3 + c3 – 3abc = (a + b + c) {(a – b)2 +(b − c)2 + (c – a)2} অথবা = (a + b + c) (a2 + b2 + c2 – ab – bc – ca)
- a3(b – c) + b3 (c – a) + c3 (a – b) = – (a – b) (b – c) (c – a) (a + b + c)