Basic Math Formulas for 11th and 12th standard students

The list of basic math formulas which is very useful for mainly 11 grade, 12 grade and college grade students. Math formulas are very important and necessary to know the correct formula while solving the questions on different topics. If we remember math formulas we can solve any type of math questions.

● Laws of Indices:

(i) a^m ∙ aⁿ = a^{m + n}

(ii) a^m/aⁿ

(iii) (a^m)ⁿ = a^mn

(iv) a⁰ = 1 (a ≠ 0).

(v) a^{- n} = 1/aⁿ

(vi) ⁿ√a^m = a^m/n

(vii) (ab)^m = a^m ∙ bⁿ.

(viii) (a/b) ^m = a^m/bⁿ

(ix) If a^m = b^m (m ≠ 0), then a = b.

(x) If a^m = aⁿ then m = n. 

● Arithmetical Progression (A.P.):

(i) The general form of an A. P. is a, a + d, a + 2d, a+3d,.....

where a is the first term and d, the common difference of the A.P.

(ii) The nth term of the above A.P. is t_n = a + (n - 1)d.

(iii) The sum of first n terns of the above A.P. is s = n/2 (a + l) = (No. of terms/2)[1st term + last term] or, S = ⁿ/₂ [2a + (n - 1) d]

(iv) The arithmetic mean between two given numbers a and b is (a + b)/2.

(v) 1 + 2 + 3 + ...... + n = [n(n + 1)]/2.

(vi) 1² + 2² + 3² +……………. + n² = [n(n+ 1)(2n+ 1)]/6.

(vii) 1³ + 2³ + 3³ + . . . . + n³ = [{n(n + 1)}/2 ]².

● Geometrical Progression (G.P.) : 

(i) The general form of a G.P. is a, ar, ar², ar³, . . . . . where a is the first term and r, the common ratio of the G.P.

(ii) The n th term of the above G.P. is t_n = a.r^{n - 1} .

(iii) The sum of first n terms of the above G.P. is S = a ∙ [(1 - rⁿ)/(1 – r)] when -1 < r < 1

or, S = a ∙ [(rⁿ – 1)/(r – 1) ]when r > 1 or r < -1.

(iv) The geometric mean of two positive numbers a and b is √(ab) or, -√(ab).

(v) a + ar + ar² + ……………. ∞ = a/(1 – r) where (-1 < r < 1).

● Arithmetical Progression (A.P.):

(i) The general form of an A. P. is a, a + d, a + 2d, a+3d,.....

where a is the first term and d, the common difference of the A.P.

(ii) The nth term of the above A.P. is t_n = a + (n - 1)d.

(iii) The sum of first n terns of the above A.P. is s = n/2 (a + l) = (No. of terms/2)[1st term + last term] or, S = ⁿ/₂ [2a + (n - 1) d]

(iv) The arithmetic mean between two given numbers a and b is (a + b)/2.

(v) 1 + 2 + 3 + ...... + n = [n(n + 1)]/2.

(vi) 1² + 2² + 3² +……………. + n² = [n(n+ 1)(2n+ 1)]/6.

(vii) 1³ + 2³ + 3³ + . . . . + n³ = [{n(n + 1)}/2 ]².

to be continue...............