Function Combination Explanation (Question 11)
Correct Answer: Option C: h = 0.5 * (g - f)
Method 1: The "2 Switches" Analogy (Sabse Aasan Tarika)
Math aur graphs ko ek second ke liye side mein rakhte hain. Isko 2 switches (buttons) ki tarah samjho jo ek timeline (left se right, -1.00 se +1.00 tak) par rakhe hain:
- Switch OFF matlab value 0.
- Switch ON matlab value 1.
1. Teeno Graphs ko Left se Right dekho:
- Graph g (Pehla Switch): Yeh shuru mein OFF (0) hai. Jaise hi hum -0.25 par pahunchte hain, yeh ON (1) ho jata hai aur aage hamesha ON rehta hai.
- Graph f (Doosra Switch): Yeh bhi shuru mein OFF (0) hai. Yeh thoda late chalu hota hai—jab hum +0.25 par pahunchte hain, tab yeh ON (1) hota hai.
- Graph h (Target Result): Hum chahte hain ki bulb sirf -0.25 se lekar +0.25 ke beech mein jale (kyunki graph h mein sirf beech mein pahad/box bana hai, baaki dono side 0 hai).
2. Sirf beech wala hissa kaise milega?
- -0.25 se +0.25 ke beech mein: Sirf g ON (1) hai, aur f abhi tak OFF (0) hai.
- +0.25 ke baad: Dono g aur f ON (1 aur 1) hain, par humein graph h mein wapas 0 (OFF) chahiye.
Dono 1 hain aur answer 0 chahiye, iska matlab minus (subtract) karna padega (1 - 1 = 0)!
Lekin f - g karein ya g - f?
- Beech wale hisse mein g = 1 hai aur f = 0 hai.
- Agar g - f karenge, toh 1 - 0 = +1 aayega (Line upar jayegi).
- Agar f - g karenge, toh 0 - 1 = -1 aayega (Line niche chali jayegi, jo galat hai).
- Isliye g - f pakka hai!
3. Yeh 0.5 kahan se aaya?
- Graph f aur g mein sabse upar number dekho (left side axis par): 1.0 likha hai. Matlab unki height 1 hai.
- Ab Graph h mein sabse upar number dekho: wahan 0.5 likha hai! Matlab h ki height aadhi (half) hai.
- Kisi bhi cheez ko aadha karne ke liye 0.5 se multiply karte hain.
Toh hamara final formula ban gaya: h = 0.5 * (g - f)
Method 2: Point Substitution (x = 0.00 Test)
Agar exam mein jaldi check karna ho, toh x-axis par x = 0.00 pick karo aur teeno graphs par uski height (y-value) dekho:
- f(0) = 0 (x = 0.00 par line niche hai)
- g(0) = 1 (x = 0.00 par line upar hai)
- h(0) = 0.5 (x = 0.00 par line top par hai, jiski height 0.5 hai)
Options Check at x = 0.00:
- A. h = f - g -> 0 - 1 = -1 (Galat)
- B. h = 0.5 * (f + g) -> 0.5 * (0 + 1) = 0.5 (x = 0 par sahi hai, par x = 0.50 par 0.5 * (1 + 1) = 1 dega jabki h(0.50) = 0 hai, toh Galat)
- C. h = 0.5 * (g - f) -> 0.5 * (1 - 0) = 0.5 (Bilkul Sahi!)
- D. h = 0.5 * (f - g) -> 0.5 * (0 - 1) = -0.5 (Galat)
Complete Region-by-Region Breakdown Table
Interval (x-axis) | f(x) ki value | g(x) ki value | g - f | h = 0.5 * (g - f) | Graph h mein kya hai? |
x < -0.25 (Left side) | 0 | 0 | 0 - 0 = 0 | 0 | 0.0 (Flat line) |
-0.25 < x < 0.25 (Middle) | 0 | 1 | 1 - 0 = 1 | 0.5 * 1 = 0.5 | 0.5 (Tower banta hai) |
x > 0.25 (Right side) | 1 | 1 | 1 - 1 = 0 | 0 | 0.0 (Wapas niche gir jata hai) |