Concept:
Ancient India made remarkable contributions in mathematics and astronomy. Several scholars wrote important scientific treatises dealing with:
• arithmetic,
• algebra,
• planetary motion,
• and astronomical calculations.
“Khandakhadyaka” is one of the important astronomical works written by the great Indian mathematician and astronomer Brahmagupta.
Step 1: Understanding Brahmagupta’s contribution.
Brahmagupta was a famous Indian mathematician and astronomer of the 7th century CE.
He made major contributions in:
• algebra,
• arithmetic,
• geometry,
• and astronomy.
His works influenced both Indian and Islamic scientific traditions.
Step 2: About the book ‘Khandakhadyaka’.
“Khandakhadyaka” is an astronomical treatise dealing with:
• planetary calculations,
• eclipse computation,
• calendrical systems,
• and astronomical observations.
The text became highly influential among later astronomers.
Step 3: Analyzing all the options carefully.
• Option (A) Aryabhatta:
Aryabhatta wrote the famous Aryabhatiya, not Khandakhadyaka.
• Option (B) Varahamihira:
Varahamihira wrote important works such as Brihat Samhita, but not Khandakhadyaka.
• Option (C) Aryadeva:
Aryadeva was associated with Buddhist philosophy rather than astronomy.
• Option (D) Brahmagupta:
Brahmagupta authored Khandakhadyaka. Therefore, this option is correct.
Step 4: Importance of Brahmagupta in mathematics.
Brahmagupta is especially remembered for:
• rules involving zero,
• treatment of negative numbers,
• algebraic equations,
• and astronomical calculations.
His scientific ideas spread beyond India and influenced global mathematics.
Step 5: Final conclusion.
Since the book Khandakhadyaka was written by Brahmagupta, the correct answer is:
\[
\boxed{\text{Brahmagupta}}
\]