Prove , if x is a rational number , x ≠ 0 then , tan(x) is not rational

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In summary, a rational number is a number that can be expressed as a ratio of two integers. The statement "x is a rational number" is only true if the condition x ≠ 0 is also true. "tan(x) is not rational" means that the trigonometric function tangent of x cannot be expressed as a ratio of two integers. We can prove this using a proof by contradiction, assuming x is a rational number and x ≠ 0. One example of a rational number x where tan(x) is not rational is x = π/4.
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prove , if x is a rational number , x ≠ 0 then , tan(x) is not rational

this theorem was proved by a mathematician called Lambert ,
I search for the proof , anyone knows it ?!
 
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FAQ: Prove , if x is a rational number , x ≠ 0 then , tan(x) is not rational

1. What is a rational number?

A rational number is any number that can be expressed as a ratio of two integers (numbers without decimals or fractions), such as 1/2, 3/4, or 5/7.

2. How can x be a rational number if x ≠ 0?

The statement "x is a rational number" is a conditional statement, meaning it is only true if the condition (x ≠ 0) is also true. This condition states that x cannot equal 0 in order for the statement to hold true.

3. What does "tan(x) is not rational" mean?

This statement means that the trigonometric function tangent of x is not a rational number. In other words, it cannot be expressed as a ratio of two integers.

4. How can you prove that tan(x) is not rational if x is a rational number and x ≠ 0?

We can prove this using a proof by contradiction. Assume that x is a rational number and x ≠ 0, and that tan(x) is a rational number. This would mean that tan(x) can be expressed as a ratio of two integers. However, we can show that this is not possible by using the fact that tan(x) = sin(x)/cos(x), and using the trigonometric identities for sin(x) and cos(x). This leads to a contradiction, proving that our assumption was false and therefore, tan(x) is not rational.

5. Can you provide an example of a rational number x where tan(x) is not rational?

Yes, one example is x = π/4. This is a rational number (3.14/4), but tan(π/4) = 1, which is not a rational number.

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