17 lines
402 B
Markdown
17 lines
402 B
Markdown
---
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title: fibonacciCountUntilNum
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tags: math,beginner
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---
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Returns the number of fibonnacci numbers up to `num`(`0` and `num` inclusive).
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Use a mathematical formula to calculate the number of fibonacci numbers until `num`.
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```js
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const fibonacciCountUntilNum = num =>
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Math.ceil(Math.log(num * Math.sqrt(5) + 1 / 2) / Math.log((Math.sqrt(5) + 1) / 2));
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```
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```js
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fibonacciCountUntilNum(10); // 7
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``` |