Explanation

A surd is a root (like a square root, cube root, etc.) that cannot be simplified into a rational number.

Examples of surds:
√2, √3, ³√5

Examples not surds:
√4 = 2 (this is a rational number)
16¹ᐟ² = 4

Key points:

• Surds are left in root form if they cannot be simplified

• They are often used in exact values in algebra, geometry, and trigonometry