Question

Which of the following is surd

• A. $\sqrt{17}$
• B. $\sqrt{4}$
• C. $2$
• D. $3$

Answer 1

Answer: (A)

$\sqrt{17}$

Surds are numbers left in 'square root form' (or 'cube root form' etc). They are therefore irrational numbers. The reason we leave them as surds is because in decimal form they would go on forever.
17 is a prime number and other than 17 and 1, it has no factor. Therefore, it cannot be simplified into a rational number. Hence $\sqrt{17}$ is a Surd.

Options B, C and D can be given simplified to rational number , hence they are not surd