All Important FormulaClass 12 Maths Notes

All Important Formula · Class 12 Maths · 6 topics.

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Topics covered in All Important Formula

  1. 1.Algebraic Formulas:

    Algebraic Formulas:

    1. (a+b)2=a2+2ab+b2

      • Expansion of a binomial square (sum of squares).

    2. (a−b)2=a2−2ab+b2(a - b)^2 = a^2 - 2ab + b^2

      • Expansion of a binomial square (difference of squares).

    3. (a+b)(a−b)=a2−b2(a + b)(a - b) = a^2 - b^2

      • Difference of squares formula.

    4. a3+b3=(a+b)(a2−ab+b2)a^3 + b^3 = (a + b)(a^2 - ab + b^2)

      • Sum of cubes.

    5. a3−b3=(a−b)(a2+ab+b2)a^3 - b^3 = (a - b)(a^2 + ab + b^2)

      • Difference of cubes.

    6. (a−b2)2=a2−2ab+b24\left(\frac{a - b}{2}\right)^2 = \frac{a^2 - 2ab + b^2}{4}

      • Square of a fraction involving binomial subtraction.

    7. a3−b3=(a−b)(a2+ab+b2)+3ab(a−b)a^3 - b^3 = (a - b)(a^2 + ab + b^2) + 3ab(a - b)

      • Another variation for the difference of cubes expansion.

    8. (a−b)4=a4−4a3b+6a2b2−4ab3+b4(a - b)^4 = a^4 - 4a^3b + 6a^2b^2 - 4ab^3 + b^4

      • Fourth power binomial expansion (difference).

    9. a3+b3=(a+b)3−3ab(a+b)a^3 + b^3 = (a + b)^3 - 3ab(a + b)

      • Sum of cubes in terms of a binomial cube.

    10. (a+b)3=a3+3a2b+3ab2+b3(a + b)^3 = a^3 + 3a^2b + 3ab^2 + b^3

      • Cube of a binomial (sum).

    11. (a−b)3=a3−3a2b+3ab2−b3(a - b)^3 = a^3 - 3a^2b + 3ab^2 - b^3

      • Cube of a binomial (difference).

    12. (a−b)3=a3−3a2b+3ab2−b3(a - b)^3 = a^3 - 3a^2b + 3ab^2 - b^3

      • Repeated cube of a binomial (difference).

    Explanation and Example of Key Formula


    Formula: (a+b)2=a2+2ab+b2(a + b)^2 = a^2 + 2ab + b^2


    • Components:
      • aa and bb are variables or numbers.
      • The square of the sum of aa and bb expands to a2+2ab+b2a^2 + 2ab + b^2.

    Example:

    Let's expand (3+2)2(3 + 2)^2:

    1. Given: a=3a = 3, b=2

      b = 2
    2. Plug into the formula: (3+2)2=32+2×3×2+22(3 + 2)^2 = 3^2 + 2 \times 3 \times 2 + 2^2
    3. Simplify: =9+12+4=25
  2. 2.Factors Formula (Logarithmic Formulas)

    1. ax=N ⟹ x=log⁡aNa^x = N \implies x = \log_a N


    • Explanation:
      If aa raised to the power xx equals NN, then xx is the logarithm of NN with base aa.

    • Example:

      If 23=82^3 = 8, then log⁡28=3\log_2 8 = 3.

    2. log⁡aa=1\log_a a = 1


    • Explanation:
      The logarithm of a number to its own base is always 1.

    • Example:

      log⁡55=1\log_5 5 = 1.

    3. log⁡1010=1\log_{10} 10 = 1


    • Explanation:
      The logarithm of 10 to the base 10 is always 1.

    • Example:

      log⁡1010=1\log_{10} 10 = 1.

    4. log⁡a(m×n)=log⁡am+log⁡an\log_a (m \times n) = \log_a m + \log_a n


    • Explanation:
      The logarithm of the product of two numbers is the sum of their logarithms to the same base.

    • Example:


      Find log⁡2(8×4)\log_2 (8 \times 4): log⁡2(8×4)=log⁡28+log⁡24\log_2 (8 \times 4) = \log_2 8 + \log_2 4 Since log⁡28=3\log_2 8 = 3 and log⁡24=2\log_2 4 = 2: log⁡2(8×4)=3+2=5\log_2 (8 \times 4) = 3 + 2 = 5

    5. log⁡a(mn)=log⁡am−log⁡an\log_a \left(\frac{m}{n}\right) = \log_a m - \log_a n


    • Explanation:
      The logarithm of the division of two numbers is the difference of their logarithms.

    • Example:


      Find log⁡2(84)\log_2 \left(\frac{8}{4}\right): log⁡2(84)=log⁡28−log⁡24\log_2 \left(\frac{8}{4}\right) = \log_2 8 - \log_2 4 Since log⁡28=3\log_2 8 = 3 and log⁡24=2\log_2 4 = 2: log⁡2(84)=3−2=1\log_2 \left(\frac{8}{4}\right) = 3 - 2 = 1

    6. log⁡amn=nlog⁡am\log_a m^n = n \log_a m


    • Explanation:
      The logarithm of a power is the exponent times the logarithm of the base number.

    • Example:

      Find log⁡282\log_2 8^2: log⁡282=2log⁡28\log_2 8^2 = 2 \log_2 8 Since log⁡28=3\log_2 8 = 3: log⁡282=2×3=6\log_2 8^2 = 2 \times 3 = 6

    7. log⁡ax2=2log⁡a∣x∣\log_a x^2 = 2 \log_a |x|


    • Explanation:
      The logarithm of x2x^2 is twice the logarithm of the absolute value of xx.

    • Example:


      Find log⁡2(−4)2\log_2 (-4)^2: log⁡2(−4)2=2log⁡2∣4∣\log_2 (-4)^2 = 2 \log_2 |4| Since log⁡24=2\log_2 4 = 2: log⁡2(−4)2=2×2=4\log_2 (-4)^2 = 2 \times 2 = 4

    8. log⁡ba×log⁡ab=1\log_b a \times \log_a b = 1


    • Explanation:
      The product of log⁡ba\log_b a and log⁡ab\log_a b is always equal to 1.

    • Example:


      If log⁡39=2\log_3 9 = 2, then log⁡93=12\log_9 3 = \frac{1}{2}, and their product: log⁡39×log⁡93=2×12=1\log_3 9 \times \log_9 3 = 2 \times \frac{1}{2} = 1

    9. log⁡ab=1log⁡ba\log_a b = \frac{1}{\log_b a}


    • Explanation:
      The logarithm of bb with base aa is the reciprocal of the logarithm of aa with base bb.

    • Example:

      If log⁡28=3\log_2 8 = 3, then log⁡82=13\log_8 2 = \frac{1}{3}.

    10. log⁡bx=log⁡axlog⁡ab\log_b x = \frac{\log_a x}{\log_a b}


    • Explanation:
      This is the change of base formula, which allows you to convert logarithms from one base to another.

    • Example:

      Find log⁡28\log_2 8 using base 10: log⁡28=log⁡108log⁡102\log_2 8 = \frac{\log_{10} 8}{\log_{10} 2} Approximate values: log⁡108≈0.903,log⁡102≈0.301\log_{10} 8 \approx 0.903, \quad \log_{10} 2 \approx 0.301 So, log⁡28≈0.9030.301=3\log_2 8 \approx \frac{0.903}{0.301} = 3

    11. log⁡ba=1log⁡ab\log_b a = \frac{1}{\log_a b}

    • Explanation: This is a repetition of Formula 9, stating the reciprocal relationship of logs.

    • Example:


      If log⁡525=2\log_5 25 = 2, then log⁡255=12\log_{25} 5 = \frac{1}{2}.
  3. 3.Trigonometric Ratios and Formulas

    📏 Trigonometric Ratios and Formulas

    1. Trigonometric Ratios:

      • tan⁡θ=sin⁡θcos⁡θ

        \tan \theta = \frac{\sin \theta}{\cos \theta}
      • cot⁡θ=cos⁡θsin⁡θ

        \cot \theta = \frac{\cos \theta}{\sin \theta}
      • sec⁡θ=1cos⁡θ

        \sec \theta = \frac{1}{\cos \theta}
      • csc⁡θ=1sin⁡θ

        \csc \theta = \frac{1}{\sin \theta}
    2. Pythagorean Identities:

      • sin⁡2θ+cos⁡2θ=1\sin^2 \theta + \cos^2 \theta = 1
      • sec⁡2θ−tan⁡2θ=1\sec^2 \theta - \tan^2 \theta = 1
      • csc⁡2θ−cot⁡2θ=1

        \csc^2 \theta - \cot^2 \theta = 1
    3. Co-function Identities:

      • sin⁡θ=cos⁡(90∘−θ)\sin \theta = \cos (90^\circ - \theta)
      • cos⁡θ=sin⁡(90∘−θ)\cos \theta = \sin (90^\circ - \theta)
      • tan⁡θ=cot⁡(90∘−θ)\tan \theta = \cot (90^\circ - \theta)
      • cot⁡θ=tan⁡(90∘−θ)\cot \theta = \tan (90^\circ - \theta)
      • sec⁡θ=csc⁡(90∘−θ)\sec \theta = \csc (90^\circ - \theta)
      • csc⁡θ=sec⁡(90∘−θ)

        \csc \theta = \sec (90^\circ - \theta)
    4. Additional Identities:

      • tan⁡θ×cot⁡θ=1\tan \theta \times \cot \theta = 1

    📊 Trigonometric Table for Common Angles



    These formulas and table help solve problems related to trigonometry, geometry, and real-world applications like physics, architecture, and engineering.

  4. 4.Differentiation Formulas

    Basic Differentiation Formulas

    1. Power Rule
      ddx(xn)=nxn−1\frac{d}{dx}(x^n) = n x^{n-1}

    2. Exponential Function
      ddx(ex)=ex\frac{d}{dx}(e^x) = e^x

    3. Logarithmic Differentiation
      ddx(log⁡ax)=1xlog⁡a

      \frac{d}{dx}(\log_a x) = \frac{1}{x \log a}

    4. Natural Logarithm
      ddx(log⁡ex)=1x

      \frac{d}{dx}(\log_e x) = \frac{1}{x}

    5. Exponential with Base aa
      ddx(ax)=axlog⁡a\frac{d}{dx}(a^x) = a^x \log a


    Trigonometric Functions

    1. Derivative of sin⁡x\sin x
      ddx(sin⁡x)=cos⁡x

      \frac{d}{dx}(\sin x) = \cos x

    2. Derivative of cos⁡x\cos x
      ddx(cos⁡x)=−sin⁡x

      \frac{d}{dx}(\cos x) = -\sin x

    3. Derivative of tan⁡x\tan x
      ddx(tan⁡x)=sec⁡2x

      \frac{d}{dx}(\tan x) = \sec^2 x

    4. Derivative of cot⁡x\cot x
      ddx(cot⁡x)=−csc⁡2x

      \frac{d}{dx}(\cot x) = -\csc^2 x

    5. Derivative of sec⁡x\sec x
      ddx(sec⁡x)=sec⁡xtan⁡x

      \frac{d}{dx}(\sec x) = \sec x \tan x

    6. Derivative of csc⁡x\csc x
      ddx(csc⁡x)=−csc⁡xcot⁡x\frac{d}{dx}(\csc x) = -\csc x \cot x


    Inverse Trigonometric Functions

    1. Derivative of sin⁡−1x\sin^{-1} x
      ddx(sin⁡−1x)=11−x2,for −1<x<1

      \frac{d}{dx}(\sin^{-1} x) = \frac{1}{\sqrt{1 - x^2}}, \quad \text{for } -1 < x < 1

    2. Derivative of cos⁡−1x\cos^{-1} x
      ddx(cos⁡−1x)=−11−x2,for −1<x<1

      \frac{d}{dx}(\cos^{-1} x) = -\frac{1}{\sqrt{1 - x^2}}, \quad \text{for } -1 < x < 1

    3. Derivative of tan⁡−1x\tan^{-1} x
      ddx(tan⁡−1x)=11+x2\frac{d}{dx}(\tan^{-1} x) = \frac{1}{1 + x^2}

    4. Derivative of cot⁡−1x\cot^{-1} x
      ddx(cot⁡−1x)=−11+x2\frac{d}{dx}(\cot^{-1} x) = -\frac{1}{1 + x^2}

    5. Derivative of sec⁡−1x\sec^{-1} x
      ddx(sec⁡−1x)=1∣x∣x2−1,∣x∣>1

      \frac{d}{dx}(\sec^{-1} x) = \frac{1}{|x| \sqrt{x^2 - 1}}, \quad |x| > 1

    6. Derivative of csc⁡−1x\csc^{-1} x
      ddx(csc⁡−1x)=−1∣x∣x2−1,∣x∣>1\frac{d}{dx}(\csc^{-1} x) = -\frac{1}{|x| \sqrt{x^2 - 1}}, \quad |x| > 1


    Hyperbolic Trigonometric Functions

    1. Derivative of sinh⁡x\sinh x
      ddx(sinh⁡x)=cosh⁡x

      \frac{d}{dx}(\sinh x) = \cosh x

    2. Derivative of cosh⁡x\cosh x
      ddx(cosh⁡x)=sinh⁡x

      \frac{d}{dx}(\cosh x) = \sinh x

    3. Derivative of tanh⁡x\tanh x
      ddx(tanh⁡x)=sech⁡2x

      \frac{d}{dx}(\tanh x) = \operatorname{sech}^2 x

    4. Derivative of coth⁡x\coth x
      ddx(coth⁡x)=−csch⁡2x

      \frac{d}{dx}(\coth x) = -\operatorname{csch}^2 x

    5. Derivative of sech⁡x\operatorname{sech} x
      ddx(sech⁡x)=−sech⁡xtanh⁡x

      \frac{d}{dx}(\operatorname{sech} x) = -\operatorname{sech} x \tanh x

    6. Derivative of csch⁡x\operatorname{csch} x
      ddx(csch⁡x)=−csch⁡xcoth⁡x

  5. 5.Integration Formulas

    1. Basic Formulas

    1. ∫1 dx=x+C

      \int 1 \, dx = x + C
    2. ∫xn dx=xn+1n+1+C\int x^n \, dx = \frac{x^{n+1}}{n+1} + C (for n≠−1n \neq -1)

    3. ∫ex dx=ex+C

      \int e^x \, dx = e^x + C
    4. ∫ax dx=axln⁡a+C\int a^x \, dx = \frac{a^x}{\ln a} + C (for a>0,a≠1a > 0, a \neq 1)

    5. ∫1x dx=ln⁡∣x∣+C\int \frac{1}{x} \, dx = \ln |x| + C

    2. Trigonometric Formulas

    1. ∫sin⁡x dx=−cos⁡x+C

      \int \sin x \, dx = -\cos x + C
    2. ∫cos⁡x dx=sin⁡x+C

      \int \cos x \, dx = \sin x + C
    3. ∫sec⁡2x dx=tan⁡x+C

      \int \sec^2 x \, dx = \tan x + C
    4. ∫csc⁡2x dx=−cot⁡x+C

      \int \csc^2 x \, dx = -\cot x + C
    5. ∫sec⁡xtan⁡x dx=sec⁡x+C

      \int \sec x \tan x \, dx = \sec x + C
    6. ∫csc⁡xcot⁡x dx=−csc⁡x+C\int \csc x \cot x \, dx = -\csc x + C

    3. Inverse Trigonometric Formulas

    1. ∫11−x2 dx=sin⁡−1x+C

      \int \frac{1}{\sqrt{1-x^2}} \, dx = \sin^{-1}x + C
    2. ∫−11−x2 dx=cos⁡−1x+C

      \int \frac{-1}{\sqrt{1-x^2}} \, dx = \cos^{-1}x + C
    3. ∫11+x2 dx=tan⁡−1x+C

      \int \frac{1}{1+x^2} \, dx = \tan^{-1}x + C
    4. ∫−11+x2 dx=cot⁡−1x+C

      \int \frac{-1}{1+x^2} \, dx = \cot^{-1}x + C
    5. ∫1xx2−1 dx=sec⁡−1∣x∣+C

      \int \frac{1}{x\sqrt{x^2-1}} \, dx = \sec^{-1}|x| + C
    6. ∫−1xx2−1 dx=csc⁡−1∣x∣+C\int \frac{-1}{x\sqrt{x^2-1}} \, dx = \csc^{-1}|x| + C

    4. Exponential and Logarithmic Functions

    1. ∫ex dx=ex+C

      \int e^x \, dx = e^x + C
    2. ∫ln⁡x dx=xln⁡x−x+C

      \int \ln x \, dx = x\ln x - x + C
    3. ∫ax dx=axln⁡a+C\int a^x \, dx = \frac{a^x}{\ln a} + C

    5. Special Forms

    1. ∫1a2+x2 dx=1atan⁡−1xa+C

      \int \frac{1}{a^2 + x^2} \, dx = \frac{1}{a} \tan^{-1} \frac{x}{a} + C
    2. ∫1a2−x2 dx=sin⁡−1xa+C

      \int \frac{1}{\sqrt{a^2 - x^2}} \, dx = \sin^{-1} \frac{x}{a} + C
    3. ∫1xx2−a2 dx=1asec⁡−1∣x∣a+C\int \frac{1}{x\sqrt{x^2 - a^2}} \, dx = \frac{1}{a} \sec^{-1} \frac{|x|}{a} + C

    6. Integration by Substitution

    If u=f(x)u = f(x), then:

    ∫f′(x)g(f(x)) dx=∫g(u) du\int f'(x)g(f(x)) \, dx = \int g(u) \, du


    7. Integration by Parts

    ∫uv dx=u∫v dx−∫(dudx∫v dx)dx\int u v \, dx = u \int v \, dx - \int \left( \frac{du}{dx} \int v \, dx \right) dx

    Where uu and vv are functions of xx.


    8. Definite Integral Properties

    1. ∫abf(x) dx=F(b)−F(a)\int_a^b f(x) \, dx = F(b) - F(a), where F(x)F(x) is the antiderivative of f(x)f(x).

    2. ∫aaf(x) dx=0

      \int_a^a f(x) \, dx = 0
    3. ∫abf(x) dx=−∫baf(x) dx
  6. 6.Exponent Laws

    Exponent Laws

    1. a0=1a^0 = 1

      • Explanation: Any non-zero number raised to the power of 00 is always 11.

    2. ap⋅aq=ap+qa^p \cdot a^q = a^{p+q}

      • Explanation: When multiplying two numbers with the same base, add the exponents.

    3. (ap)q=ap⋅q(a^p)^q = a^{p \cdot q}

      • Explanation: When raising a power to another power, multiply the exponents.

    4. apaq=ap−q\frac{a^p}{a^q} = a^{p-q}

      • Explanation: When dividing two numbers with the same base, subtract the exponents.

    5. a−n=1ana^{-n} = \frac{1}{a^n}

      • Explanation: A negative exponent means the reciprocal of the number raised to the positive exponent.

    6. a=a1/2\sqrt{a} = a^{1/2}

      • Explanation: The square root of a number can be expressed as the number raised to the power 1/21/2.

    7. a3=a1/3\sqrt[3]{a} = a^{1/3}

      • Explanation: The cube root of a number can be expressed as the number raised to the power 1/31/3.

    8. an=a1/n\sqrt[n]{a} = a^{1/n}

      • Explanation: The nn-th root of a number can be expressed as the number raised to the power 1/n1/n.

    9. a1=aa^1 = a

      • Explanation: Any number raised to the power 11 is the number itself.

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