বীজগণিতেরর সূত্র


বীজগণিতেরর সূত্র ও অনুসিদ্ধান্তঃ

1. (a+b)²= a²+2ab+b²
2. (a+b)²= (a-b)²+4ab
3. (a-b)²= a²-2ab+b²
4. (a-b)²= (a+b)²-4ab
5. a² + b²= (a+b)² – 2ab.
6.a² + b²= (a-b)² + 2ab.
7. a²-b² =(a +b)(a – b)
8. 2(a² + b²) = (a+ b)² + (a – b)²
9. 4ab = (a + b)² -(a-b)²
10. ab ={(a+b)/2}²-{(a-b) /2}²
11. (a + b + c)² = a² +b² + c² + 2(ab + bc+ca)
12. (a + b)³ =a³ + 3a²b + 3ab² + b³
13. (a + b)³ = a³+ b³ + 3ab (a + b)
14. a-b)³=a³-3a²b+3ab²- b³
15.(a-b)³=a³- b³-3ab(a-b)
16. a³ + b³ = (a + b) (a² -ab+ b²)
17. a³ + b³ = (a+ b)³ -3ab(a + b)
18. a³ -b³ = (a -b) (a² + ab + b²)
19. a³-b³ = (a-b)³ + 3ab(a- b)



  1. sin(A + B) = sinA.cosB + cisA.sinB
  2. sin(A - B) = sinA.cosB - cisA.sinB
  3. cos(A + B) = cosA.cosB - sinA.sinB
  4. cos(A - B) = cosA.cosB + sinA.sinB
  5. tan(A + B) = tanA + tanB1 - tanA.tanB
  6. tan(A - B) = tanA - tanB1 + tanA.tanB
  7. cot(A + B) = cotA.cotB - 1cotA + cotB
  8. cot(A - B) = cotA.cotB + 1cotB - cotA
  9. sin(A + B).sin(A - B) = sin2A - sin2B = cos2B - cos2A
  10. cos(A + B).cos(A - B) = cos2A - sin2B = cos2B - sin2A