Aryabhata, a renowned Indian mathematician and astronomer, is credited with laying the foundation of Indian trigonometry in the 5th century CE.

Aryabhata made significant contributions to trigonometry, including the introduction of the sine function and the development of a table of sines, which greatly facilitated trigonometric calculations.

Brahmagupta's treatise, titled 'Brahmasphuta Siddhanta,' is a comprehensive work that includes significant contributions to trigonometry, such as formulas for calculating the sine and cosine of angles.

Bhaskara II, a prominent Indian mathematician, introduced the concept of the versine function and provided a formula for its calculation, further enriching the field of trigonometry.

Varahamihira's astronomical text, known as 'Surya Siddhanta,' includes trigonometric formulas and tables, demonstrating the integration of trigonometry in ancient Indian astronomy.

Bhaskara II devised a method for solving trigonometric equations using geometric constructions, showcasing the practical applications of trigonometry in solving real-world problems.

Aryabhata's treatise, titled 'Aryabhatiya,' includes trigonometric formulas and tables, establishing his contributions to the field.

Brahmagupta derived a formula for calculating the area of a triangle using trigonometric functions, demonstrating the versatility of trigonometry in solving geometric problems.

Bhaskara II's astronomical text, known as 'Siddhanta Shiromani,' includes trigonometric formulas and tables, further enriching the body of knowledge in trigonometry.

Bhaskara II devised a method for solving trigonometric equations using algebraic techniques, expanding the scope of trigonometry beyond geometric constructions.

Varahamihira's treatise, titled 'Pancasiddhantika,' includes trigonometric formulas and tables, showcasing his contributions to the field.

Bhaskara II derived a formula for calculating the sine of an angle using the half-angle formula, demonstrating his mastery of trigonometric identities.

Aryabhata's treatise, titled 'Aryabhatiya,' includes trigonometric formulas and tables, establishing his contributions to the field.

Bhaskara II devised a method for solving trigonometric equations using graphical techniques, expanding the range of methods available for solving such equations.

Varahamihira's treatise, titled 'Pancasiddhantika,' includes trigonometric formulas and tables, showcasing his contributions to the field.