Mathematics

Mathematics

Problem

Find the value of f(2.7)f(2.7), where f(x)=⌊x⌋+sgn⁡(x)f(x)=\lfloor x\rfloor+\operatorname{sgn}(x). a) 44 b) 2.72.7 c) 33 d) 22
Intuitive explanation

The floor function ⌊x⌋\lfloor x \rfloor gives you the greatest integer less than or equal to xx, while the sign function sgn⁡(x)\operatorname{sgn}(x) simply tells you whether xx is positive, negative, or zero. For a positive number like 2.7, you need to find both pieces separately and add them together—the key is recognizing that ⌊2.7⌋\lfloor 2.7 \rfloor is straightforward, and sgn⁡(2.7)\operatorname{sgn}(2.7) is just asking "is this positive or negative?"

Intuitive explanation

The floor function ⌊x⌋\lfloor x \rfloor gives you the greatest integer less than or equal to xx, while the sign function sgn⁡(x)\operatorname{sgn}(x) simply tells you whether xx is positive, negative, or zero. For a positive number like 2.7, you need to find both pieces separately and add them together—the key is recognizing that ⌊2.7⌋\lfloor 2.7 \rfloor is straightforward, and sgn⁡(2.7)\operatorname{sgn}(2.7) is just asking "is this positive or negative?"

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