what are the formulas of expansion??
Answers
1. (a + b)2 = a2 + 2ab + b2; a2 + b2 = (a + b)2 − 2ab
2. (a − b)2 = a2 − 2ab + b2; a2 + b2 = (a − b)2 + 2ab
3. (a + b + c)2 = a2 + b2 + c2 + 2(ab + bc + ca)
4. (a + b)3 = a3 + b3 + 3ab(a + b); a3 + b3 = (a + b)3 − 3ab(a + b)
5. (a − b)3 = a3 − b3 − 3ab(a − b); a3 − b3 = (a − b)3 + 3ab(a − b)
6. a2 − b2 = (a + b)(a − b)
7. a3 − b3 = (a − b)(a2 + ab + b2)
8. a3 + b3 = (a + b)(a2 − ab + b2)
9. an − bn = (a − b)(an−1 + an−2b + an−3b2 + ··· + bn−1)
10. an = a.a.a . . . n times
11. am.an = am+n
12. am
an = am−n if m>n
= 1 if m = n
= 1
an−m if m<n; a ∈ R, a 6= 0
13. (am)n = amn = (an)m
14. (ab)n = an.bn
15. a
b
n
= an
bn
16. a0 = 1 where a ∈ R, a 6= 0
17. a−n = 1
an , an = 1
a−n
18. ap/q = √q ap
19. If am = an and a 6= ±1, a 6= 0 then m = n
20. If an = bn where n 6= 0, then a = ±b
21. If √x, √y are quadratic surds and if a + √x = √y, then a = 0 and x = y
22. If √x, √y are quadratic surds and if a+ √x = b+ √y then a = b and x = y
23. If a, m, n are positive real numbers and a 6= 1, then loga mn = loga m+loga n
24. If a, m, n are positive real numbers, a 6= 1, then loga
m
n
= loga m−loga n
25. If a and m are positive real numbers, a 6= 1 then loga mn = n loga m
26. If a, b and k are positive real numbers, b 6= 1, k 6= 1, then logb a = logk a
logk b
27. logb a = 1
loga b where a, b are positive real numbers, a 6= 1, b 6= 1
28. if a, m, n are positive real numbers, a 6= 1 and if loga m = loga n, then
m = n
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2
29. if a + ib = 0 where i = √−1, then a = b = 0
30. if a + ib = x + iy, where i = √−1, then a = x and b = y
hope this is the write answer and also helpful
