Final answer:
Islamic mathematicians dealt with irrational numbers by approximating them as fractions, contributing significantly to the development of algebra and trigonometry. Using Arabic numerals and advancements in mathematical theory, they also made practical applications in fields like astronomy and navigation. Option B is the correct answer.
Step-by-step explanation:
Islamic mathematicians dealt with irrational numbers by approximately representing them as fractions. This approach provided a practical method for working with numbers that cannot be expressed as exact ratios of integers. They did not ignore irrational numbers nor predominantly use radical symbols or the base 60 system for their representation in general mathematical practices. Islamic scholars contributed significantly to the advancement of mathematics, inventing algebra and trigonometry. The Abbasids, for instance, utilized Arabic numerals based on Hindu characters, which were easier to work with than Roman numerals.
The widespread use of the decimal positional number system, along with the critical innovations such as algebra introduced by medieval Persian mathematicians like Muhammad ibn Musa al-Khwarizmi, further exemplifies the Islamic mathematicians' capacity to handle complex mathematical concepts, including irrational numbers.
Moreover, Islamic mathematicians excelled in fields such as astronomy and navigation, using mathematical calculations for practical purposes like determining prayer directions (qibla) with precision. This legacy of Islamic mathematics, enriched through exchanges with Indian and Persian intellectual traditions, laid foundational tools for future scientific progress.
In conclusion, the correct option is b) They approximated them as fractions.