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# C3 Question watch

1. Could anyone help I'm stuck on question 4 part iii on this paper
https://7c95ed1f832973eac0c6e1a52b08...20C3%20OCR.pdf

I'm not even sure I understand the question, and I have no idea how the answer
'0 < k <= 2' relates to the question because i thought the equation f(x) = 2 - x^(1/2) only had one root
2. (Original post by JW22)
Could anyone help I'm stuck on question 4 part iii on this paper
https://7c95ed1f832973eac0c6e1a52b08...20C3%20OCR.pdf

I'm not even sure I understand the question, and I have no idea how the answer
'0 < k <= 2' relates to the question because i thought the equation f(x) = 2 - x^(1/2) only had one root
Since the function is strictly decreasing (see the graph or differentiate), in order for there to be two distinct roots, we must have and , as then .
Can you see now why the given range is the answer?
3. (Original post by joostan)
Since the function is strictly decreasing (see the graph or differentiate), in order for there to be two distinct roots, we must have and , as then .
Can you see now why the given range is the answer?
Yes thanks!

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