Mathematics for IGCSE & O level - Surds (Section 2 - No. 36)
Which of the following results in a rational number?
√2 * √8
3 + √5 - √5
1 / √2
(√3+1) * (√3-1)
Vysvětlení
A, B and D. √2 * √8 = 4, 3 + √5 - √5 = 3 and (√3+1) * (√3-1) = 3 - 1 = 2 are rational numbers