If the function f : (−∞, ∞) → B defined by f(x) = -x2 + 6x - 8 is onto, then B is equal to :
Answer & explanation
Correct answer: option 1
We have to find B such that f(x) because onto ⇒ B should be equal to range of f(x).
Now f(x) = 1 – (x – 3)2
⇒ Range = (–∞, 1] = B
Hence (1) is the correct answer.