4.2.2 · D1 · Maths › Calculus II — Integration › Basic integration rules — power, trig, exponential, log
Integration kuch aur nahi balki differentiation ko ulta chalana hai: tumhe ek rate of change diya jata hai aur puchha jata hai ki woh kis function se aayi. Us machine ko backwards padhne ke liye pehle tumhe forward machine — notation, pictures, aur rules — poori tarah samajhni hogi — isliye yeh page woh har symbol build karta hai jo parent note quietly assume karta hai, ek blank page se shuru karke.
Isse pehle ki tum "derivative rules ko backwards padho" enjoy karo, tumhe yakeen hona chahiye ki page par har squiggle ka matlab kya hai. Neeche, har symbol unpack kiya gaya hai: seedhe words → picture → aur topic ko uski zaroorat kyun hai. Upar se neeche padho; koi cheez use nahi hoti jab tak build nahi ho jaati.
Ek function ek rule hai jo ek input number leta hai aur exactly ek output number deta hai. Hum f ( x ) likhte hain, padha jaata hai "f of x ", matlab "rule f ka output jab input x ho."
Iska picture ek graph hai: har horizontal position x ke liye, curve f ( x ) ki height par baithi hoti hai. Woh height hi ek function hota hai — ek height jo is baat par depend karti hai ki tum kahan khade ho.
Intuition Topic ko iska kya zaroorat hai
Har integral ∫ f ( x ) d x ek function f se start hota hai. Agar tum f ( x ) ko "number line ke upar ek height" ke roop mein picture nahi kar sakte, toh baaki sab sirf symbol-shuffling hai. Blue curve dekho: number f ( x ) dashed vertical line ki length hai.
Definition Variable of integration
x woh input hai jise hum change karne ke liye free hain . Integral ke end mein chhota d x ek tag hai jo kehta hai: "woh variable jiske upar main integrate kar raha hoon woh x hai" — yeh sirf knob ka naam batata hai (abhi ke liye).
Socho ek slider jise tum horizontal axis ke saath left aur right push kar sakte ho. Woh slider hi x hai. Symbol d x us slider ki ek nudge hai — thodi si right ki taraf ek step.
Intuition Topic ko iska kya zaroorat hai
∫ … d x vs ∫ … d t batata hai ki kaun sa letter moving hai aur kaun se letters frozen constants hain. Agar yeh miss kiya toh tum variable aur constant mein farak nahi kar sakte.
Ek seedhi line ka slope yeh hai ki "jab tum ek step right lete ho toh height kitni badhti hai": slope = run rise . Tezi se upar jaana ek bada positive slope hai; flat 0 hai; neeche jaana negative hai.
Ek curve ke liye, slope chalte waqt badalta rehta hai. Har point par hum tangent line kheenchte hain — woh seedhi line jo curve ko wahan just kiss karti hai — aur uska slope padhte hain.
f ka derivative , likha d x d f ( x ) ya f ′ ( x ) , ek nayi function hai jiska value har x par f ka us x par slope hai. d x d ko "...ka slope-rate" padho.
Intuition Topic ko iska kya zaroorat hai — yeh POORA topic ulta hai
Parent note ka motto hai "integration is anti-differentiation." Woh sentence meaningless hai jab tak d x d bilkul solid na ho. Green figure mein, orange tangent ki steepness har point par exactly wahi hai jo f ′ ( x ) record karta hai. Integration poochhhta hai: har jagah ki steepness di gayi ho, original curve wapas banao.
Forward rules ke liye Derivatives — basic rules dekho; har integral rule unme se ek ulti hai.
f ′ ( x ) (bola jaata hai "f prime of x ") ka matlab exactly wahi hai jo d x d f ( x ) ka hai: f ki slope-function. Prime compact costume hai; d x d "mujhe knob dikhaao" wala costume hai.
Parent note dono likhta hai — jaise "F ′ ( x ) = f ( x ) " aur "d x d sin x = cos x ". Yeh interchangeable hain. d x d tab use karo jab tum kaun sa variable hai is baat ke baare mein loud rehna chahte ho; f ′ tab use karo jab yeh obvious ho.
∫ f ( x ) d x padha jaata hai "the integral of f with respect to x ." Symbol ∫ ek stretched letter S hai (yeh kabhi Sum ke liye tha). Abhi ke liye, poori cheez ko ek sawaal ki tarah treat karo: "kaun si function ka slope f ( x ) hai?"
Definition Constant of integration
Answer F ( x ) + C mein ==+ C == shamil hai, ek unknown constant. Iska picture: ek puri family of parallel curves , sab ki slope har x par identical, sirf vertical shift mein alag.
+ C humpar forced hai
Slope sirf shape batata hai, kabhi height nahi. Figure mein teen curves hain x 2 , x 2 + 7 , x 2 − 4 — shifted copies, sab ki tangent slope har x par 2 x same hai. Kyunki differentiation shift ko 0 kar deta hai, isse ulta chalane se yeh recover nahi ho sakta ki tumne kaunsi shift se shuru kiya tha. Hum woh ignorance + C likh ke maan lete hain.
Ek antiderivative F koi bhi function hai jiske liye F ′ ( x ) = f ( x ) ho. Shift-family ki wajah se, infinitely many hain — exactly yahi + C capture karta hai.
Definition Powers, roots, aur negative/fraction exponents
x n matlab "x ko khud se n baar multiply karo" jab n ek whole number ho.
x − 1 = x 1 , aur generally x − k = x k 1 — ek negative exponent matlab reciprocal (palat do).
x 1/2 = x , aur x 1/2 matlab "woh number jo square karke x deta hai" — ek fraction exponent matlab root .
Intuition Topic ko iska kya zaroorat hai
Power rule ∫ x n d x = n + 1 x n + 1 + C tabhi kaam karta hai jab tum kuch bhi x kuch ke roop mein likh sako: x → x 1/2 , x 3 4 → 4 x − 3 . Parent note ke Worked Example 1 aur 2 is rewriting par hi depend karte hain.
Worked example Rewrite drills (parent ke examples se)
x = x 1/2
x 3 4 = 4 x − 3
x 6 = 6 x − 1 (yeh forbidden n = − 1 case hai — §7 dekho)
Definition Absolute value
∣ x ∣ matlab "x ki size, hamesha non-negative": ∣5∣ = 5 aur ∣ − 5∣ = 5 . Isse zero se distance samjho, direction ignore karte hue.
Log rule hai ∫ x 1 d x = ln ∣ x ∣ + C . Bars isliye aate hain kyunki x 1 negative x ke liye bhi sense karta hai, lekin plain ln x nahi karta — toh ∣ x ∣ domain ko sab x = 0 tak patch karta hai.
e aur natural log ln
e ≈ 2.718 ek fixed special number hai. ln x (natural log) ek ==sawaal hai "e ki kaun si power x deti hai?"== — yeh e x ko undo karta hai. Iska slope famous taur par d x d ln x = x 1 hai, jo exactly wahi hai jo log integral rule ulta karta hai.
Intuition Topic ko iska kya zaroorat hai
Do parent rules is par depend karte hain: ∫ e x d x = e x + C (kyunki e x apna khud ka slope hai) aur ∫ a x d x = ln a a x + C . Inhe Natural log and exponential functions mein theek se milo.
Definition Sine aur cosine
Ek point ko radius 1 ke circle ke around counter-clockwise ghoomne do. cos x uski horizontal position hai, sin x uski vertical position, jahan x ghuma hua angle hai. Dono hamesha ke liye − 1 aur 1 ke beech mein ghoomte rehte hain — woh endless wiggle hi wajah hai ki unke slopes ek doosre mein badal jaate hain.
Definition Family ke baaki members
tan x = cos x sin x
sec x = cos x 1 , csc x = sin x 1 , cot x = sin x cos x
Intuition Topic ko iska kya zaroorat hai — aur minus-sign trap
Forward slopes hain d x d sin x = cos x aur d x d cos x = − sin x . Woh cosine side par minus ek hi fact hai jo parent ke "sign trap" ke peeche hai: ∫ sin x d x = − cos x + C , + cos x nahi. Figure mein red horizontal shadow dekho — jaise point upar jaata hai, horizontal shadow cos x shrink karta hai, aur woh shrinking negative slope hai. Iske aur examples Trigonometric integrals mein hain.
"Linear" matlab do freedoms: tum ek sum ko alag-alag pieces mein split kar sakte ho, aur ek constant multiplier ko bahar nikal sakte ho. Kyunki differentiation d x d [ a f + b g ] = a f ′ + b g ′ follow karta hai, integration ko ulte mein same freedom milti hai.
Common mistake Tempting non-rule
Integrals ke liye koi product rule ya quotient rule nahi hai. Aise lagta hai jaise differentiation ek de deta, lekin nahi deta — products ke liye Integration by parts aur composites ke liye Integration by substitution chahiye.
Function f of x as a height
Derivative slope function
Exponents powers roots negatives
Sine cosine on the circle
Linearity split and scale
Integration anti differentiation plus C
Har arrow same destination par jaata hai: parent topic bas yahi foundations hain, ulte padhe, aur + C lagaya.
f ( x ) ka picture ke roop mein kya matlab hai?Horizontal axis par point x ke upar curve ki height.
Ek sentence mein derivative f ′ ( x ) kya hai? Ek nayi function jo har x par f ki tangent line ka slope batati hai.
Kya f ′ ( x ) aur d x d f ( x ) same hain? Haan — identical meaning, slope-function ke liye do notations.
Kyun har indefinite integral + C pe khatam hota hai? Slope sirf shape fix karta hai, vertical height nahi; differentiation kisi bhi constant ko 0 kar deta hai, isliye hum use recover nahi kar sakte.
x , x 3 4 , aur x 6 ko powers ke roop mein likho.x 1/2 , 4 x − 3 , 6 x − 1 .
Negative exponent x − k ka kya matlab hai? Reciprocal, x k 1 .
Log integral mein x ki jagah ∣ x ∣ kyun use hota hai? x 1 negative x ke liye bhi defined hai; ∣ x ∣ antiderivative ko sab x = 0 tak extend karta hai.
ln x kya poochh raha hai?"e ki kaun si power x deti hai?" — yeh e x ko undo karta hai.
Unit circle par kaun sa coordinate cos x hai? Moving point ka horizontal coordinate.
Kaun si trig slope minus sign carry karti hai? d x d cos x = − sin x — ∫ sin x d x = − cos x trap ka source.
Linearity tumhe kaun si do freedoms deti hai? Sum ko alag-alag integrals mein split karo; constant multipliers ko bahar nikalo.
Kya integration ke liye koi product rule hai? Nahi — iske liye integration by parts ya substitution use karo.