Explanation
Is sawal ko solve karne ke liye, aap equation ko aise likh sakte hain:
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Intervals break karein: x < -2, -2 \le x < 1, aur x≥1.
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Graph draw karein: f(x) ka graph banakar dekhein ki horizontal line y=−a graph ko sirf ek jagah kab cut karti hai.
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Local Maxima/Minima: Check karein ki function monotonic hai ya nahi. Is case mein, f(x) hamesha badhne wala (strictly increasing) function nikalta hai, isliye a ki kisi bhi real value ke liye hamesha ek hi root hoga.
Correct Option: (2) (−∞,∞)