Category: MATHEMATICS MADE EASY

  • Understanding Calculus

    Integral Calculus

    What Is Integration?

    Integration is just:

    👉 Adding tiny pieces together to get the whole.

    That’s it.
    Not demons.
    Not wizard math.
    Just adding small bits.

    Imagine This Example

    You have a bucket.
    Someone pours water into it very slowly, drop by drop.

    You want to know:

    How much water is inside after some time?

    You can’t count each drop one by one — too many.

    So you add all the tiny drops together.

    That “adding small, small pieces” is integration.

    See It Another Way

    Imagine you’re painting a wall with tiny dots

    Each dot is small, but together they fill the whole wall.

    Integration = adding all the dots.

    How Is Integration Connected to Differentiation?

    Differentiation breaks things into tiny pieces (rates).
    Integration puts tiny pieces back together.

    Differentiation = breaking

    Integration = rebuilding

    They’re opposites — like tying and untying shoelaces.

    The Symbol for Integration

    \int

    That long S-shaped symbol ∫ means:

    “Sum up everything.”

    Differentiation helps us describe how fast something is changing (rate of change). Anti-differentiation (integration) helps us find the original quantity or the total accumulated amount from that rate.

    So, if differentiation answers “How fast is it changing?”,

    Anti-differentiation (Integration) answers

    How much has changed in total?” and “What original function produced this rate?”

    Meaning of Anti-differentiation

    If a function F(x) is such that 

    ddx[F(x)]=f(x) \frac{d}{dx}[F(x)] = f(x)

    then F(x) is an antiderivative of f(x).

    We write the indefinite integral as:

    f(x)dx=F(x)+C∫ f(x) dx = F(x) + C 

    where C is the constant of integration.

    Why do we add C?

    Because many different functions have the same derivative.

    For instance,

    ddx(x2)=2x \frac{d}{dx}(x²) = 2x

    and

    ddx(x2+7)=2x \frac{d}{dx} (x²+7) = 2x

    So the antiderivative of 2x is .

    x2+Cx² + C

    Basic Rules (Indefinite Integrals)

    1. Power Rule

    xndx=+C(n1)∫ xⁿ dx =   +  C   (n ≠ −1)

     Add 1 to the power

    Divide by the new power

    Add + C

    xn+1n+1dx+C\frac{x^{n+1}}{n + 1}dx + C

    2. Constant Multiple Rule

    kf(x)dx=kf(x)dx∫ k f(x) dx = k ∫ f(x) dx

    3. Sum/Difference Rule

    [f(x)±g(x)]dx=f(x)dx±g(x)dx∫ [f(x) ± g(x)] dx = ∫ f(x) dx ± ∫ g(x) dx

    4. Important Special Case

    1xdx=ln|x|+C∫ \frac{1}{x} dx = ln|x| + C

    Definite Integrals and Total Accumulation

    abf(x)dx=F(b)F(a)∫ₐᵇ f(x) dx = F(b) − F(a)

    This is the Fundamental Theorem of Calculus. It gives the total accumulated amount of f(x) from a to b. In many cases, it also represents area under the curve, but the “area” can mean real scientific quantities.

    Uses of Integration

    Integration helps to:

    find area under curves

    find distance traveled

    calculate volume

    solve physics problems

    Example 1

    Evaluate:

    (6x24x+9)dx ∫ (6x^2 − 4x + 9) dx

    Solution

    (6x24x+9)dx∫ (6x^2 − 4x + 9) dx
    =6x2dx4xdx+9dx= ∫ 6x^2 dx − ∫ 4x dx + ∫ 9 dx
    =6.x334.x22+9x\frac{}{} = 6.\frac{x^3}{3} − 4.\frac{x^2}{2} + 9x
    =2x32x2+9x+C= 2x^3 – 2x^2 + 9x + C

    Example 2

    Evaluate:

    (5x4+3x7)dx ∫ (5x^4 + 3x − 7) dx

    Solution

    (5x4+3x7)dx∫ (5x^4 + 3x − 7) dx
    5x4dx+3xdx7dx∫ 5x^4 dx + ∫ 3x dx − ∫ 7 dx
    5.x55+3x227+C5.\frac{x^5}{5} + 3\frac{x^2}{2} – 7 + C
    x5+3x227x+Cx^5 + \frac{3x^2}{2} – 7x + C

    Example 3

    Evaluate:(3x+2x3)dxEvaluate: ∫ (\frac{3}{x} + 2x^3) dx

    Solution:

    (3x+2x3)dx∫ (\frac{3}{x} + 2x^3) dx
    31xdx+3x3dx3∫ \frac{1}{x} dx + 3∫ x^3dx
    3ln|x|+x44+C3 ln|x| + \frac{x^4}{4} + C
    3ln|x|+x44+C3 ln|x| + \frac{x^4}{4} + C

    Example 4

    Evaluate

    251xdx\int_{2}^{5} \frac{1}{x}\, dx

    Solution

    1xdx=lnx+C\int \frac{1}{x}\, dx = \ln x + C
    251xdx\int_{2}^{5} \frac{1}{x}\, dx
    =[lnx]25= \left[ \ln x \right]_{2}^{5}
    =ln5ln2= \ln 5 – \ln 2
    =ln(52)= \ln\left( \frac{5}{2} \right)

    Example 5

    0πsinxdx\int_{0}^{\pi} \sin x \, dx

    Solution

    sinxdx=cosx+C\int \sin x\, dx = -\cos x + C
    0πsinxdx\int_{0}^{\pi} \sin x\, dx
    =[cosx]0π= \left[ -\cos x \right]_{0}^{\pi}
    =(cosπ)(cos0)= \left( -\cos \pi \right) – \left( -\cos 0 \right)
    =(1)(1)= -(-1) – ( -1 )
    22

    Example 6

    14xdx\int_{1}^{4} x\, dx

    Solution

    xdx\int x\, dx
    =x22+C= \frac{x^2}{2} + C
    14xdx\int_{1}^{4} x\, dx
    =[x22]14= \left[ \frac{x^2}{2} \right]_{1}^{4}
    =16212= \frac{16}{2} – \frac{1}{2}
    =812= 8 – \frac{1}{2}
    =152= \frac{15}{2}

    Example 7

    Find the area under the curve

    y=4x2fromx=0tox=2y = 4 – x^2 from x = 0 to x = 2

    Solution

    Area=02(4x2)dx\text{Area} = \int_{0}^{2} (4 – x^2)\, dx
    (4x2)dx\int (4 – x^2)\, dx
    =4xx33= 4x – \frac{x^3}{3}
    =[4xx33]02= \left[4x – \frac{x^3}{3} \right]_{0}^{2}
    =(883)(00)= \left( 8 – \frac{8}{3} \right) – (0 – 0)
    =24383= \frac{24}{3} – \frac{8}{3}
    =163= \frac{16}{3}

    Example 8

    A particle moves with velocity

    v(t)=3t2+2t.v(t)=3t ^2 +2t.
    Find the distance travelledFind\ the\ distance\ travelled
     from t=0 to t=3.\ from\ t=0\ to\ t=3.

    Solution

    Distance=03(3t2+2t)dt\text{Distance} = \int_{0}^{3} (3t^2 + 2t)\, dt
    (3t2+2t)dt\int (3t^2 + 2t)\, dt
    =t3+t2= t^3 + t^2
    Distance=[t3+t2]03\text{Distance} = \left[ t^3 + t^2 \right]_{0}^{3}
    =(27+9)(0+0)= (27 + 9) – (0 + 0)
    =36 units= 36 \text{ units}

  • How to Stop Struggling with Math

    5 Tips for Students Who “Just Don’t Get It”

    We’ve all been there. You’re sitting at a desk, staring at a math problem that looks more like ancient hieroglyphics than anything recognizable. You’ve re-read the textbook chapter three times, but the numbers just aren’t clicking.

    The frustration builds, and that familiar thought creeps in:

    Here is the truth that nobody tells you often enough: Struggling with math does not mean you are bad at it. It usually just means you haven’t found the right way to unlock it yet.

    Math isn’t about being born with a special “math gene.” It is a skill, much like learning to play an instrument or a sport. If you feel like you’re hitting a wall, it’s often a sign that your approach needs to shift, not your brain

    If you are tired of feeling lost in class and want to finally stop fighting with your homework, here are five actionable tips to help you turn things around.

    1. Stop Memorizing, Start Understanding

    One of the biggest traps students fall into is trying to memorize formulas and steps without understanding why they work.

    This might get you through a quiz on Tuesday, but by Friday, you’ll have forgotten everything. Math is cumulative. If you rely on memorization, the moment you face a problem that looks slightly different, you’ll freeze.

    2. Master the “Basics” First (The Gap Theory)

    Math is like a towering skyscraper. If the foundation on the 5th floor is shaky, you cannot build the 20th floor. Many students struggle with advanced Algebra not because Algebra is too hard, but because they never fully mastered fractions or multiplication tables from years earlier. This is called “The Gap Theory.”

    3. Practice “Active” Problem Solving

    Watching a teacher solve a problem on the board is like watching a chef cook a meal on TV. It looks easy when they do it, but the moment you step into the kitchen, you realize you don’t know how to hold the knife.

    Passive studying (reading notes, watching videos) gives you a false sense of confidence. You actually have to get your hands dirty.

    4. Use the “Feynman Technique”

    This is arguably the most effective study method for difficult subjects. The concept is simple: You don’t truly understand something unless you can explain it in simple terms.

    5. Change Your Relationship with Mistakes

    In English class, a red mark means you made a mistake. In math, a wrong answer is just data.

    Math anxiety often comes from a fear of being wrong. But in the world of mathematics, finding out why an answer is wrong is the only way to find the right one. Every time you fix a mistake, your brain creates a stronger neural pathway.

    The Bottom Line

    You are capable of understanding math. It requires patience, a shift in mindset, and a willingness to try new methods. Stop telling yourself you “just don’t get it,” and start telling yourself, “I don’t get it yet.”

  • From Confusion to Understanding

    At first, some questions can look very confusing. You read them and feel unsure of what to do. This happens to everyone, and it is normal.

    After a few days of practice, things begin to change. You start to recognize patterns. You may say to yourself, “Oh, this is like the one we did yesterday,” or “This is a simultaneous equation.” Sometimes you quickly realize, “This needs factorization,” or “I’ve used this method before.”

    This is how learning works. Understanding does not always come immediately. It grows with practice and repeated exposure.

    So when a question feels hard at first, don’t be discouraged. Keep practicing. With time, what once looked confusing will start to feel familiar, and that is a sign of real learning.

  • Practice One Maths Problem a Day

    A lot of students have said this at some point:

    “I understand what you’re saying… but I don’t know how we arrived at that answer.”

    If that sounds like you, you’re not alone. It’s one of the most common problems in Mathematics, not because you’re not smart, but because Maths is not a “read-and-forget” subject. Maths is a do-it subject.

    And one simple habit can change everything:

    Solve one Mathematics problem every day.