- expand_trigo(`cos(a+b)`) returns `cos(a)*cos(b)+sin(a)*sin(b)`
- expand_trigo(`cos(a-b)`) returns `cos(a)*cos(b)-sin(a)*sin(b)`
- expand_trigo(`sin(a-b)`) returns `cos(a)*sin(b)-sin(a)*cos(b)`
- expand_trigo(`sin(a+b)`) returns `cos(a)*sin(b)+sin(a)*cos(b)`

The calculator makes it possible to obtain the trigonometric expansion of an expression.

The calculator makes it possible to calculate online the **trigonometric expansion** of an expression which
involves sines or cosines, for this it uses the duplication formulas associated with these functions.
The calculator makes it possible to make symbolic calculations, it is therefore possible to combine numbers and letters.

The calculator can make **trigonometric expansions of expression** of the form
cos(a+b) by giving the results in exact form : thus to expand
`cos(pi/6+pi/3)`, enter
expand_trigo(`cos(pi/6+pi/3)`),
after calculation, the result is returned.

The calculator can expand **trigonometric formulas** of the form
cos(a-b) by giving the results in exact form : thus to expand
`cos(pi/6-pi/3)`, enter
expand_trigo(`cos(pi/6-pi/3)`),
after calculation, the result is returned.

The calculator can also make **trigonometric expansions of formula** of the form
`sin(a+b)` by giving the results in exact form : thus to expand
`sin(pi/6+pi/3)`, enter
expand_trigo(`sin(pi/6+pi/3)`),
after calculation, the result is returned.

The calculator can expand make **trigonometric expressions** of the form
`sin(a-b)` by giving the results in exact form : thus to expand
`sin(pi/6-pi/3)`, enter
expand_trigo(`sin(pi/6-pi/3)`),
after calculation, the result is returned.

expand_trigo(expression), where expression is a trigonometric expression

- expand_trigo(`cos(a+b)`) returns `cos(a)*cos(b)+sin(a)*sin(b)`
- expand_trigo(`cos(a-b)`) returns `cos(a)*cos(b)-sin(a)*sin(b)`
- expand_trigo(`sin(a-b)`) returns `cos(a)*sin(b)-sin(a)*cos(b)`
- expand_trigo(`sin(a+b)`) returns `cos(a)*sin(b)+sin(a)*cos(b)`

See also

- Arccosine : arccos. The arccos function allows the calculation of the arc cosine of a number. The arccos function is the inverse functions of the cosine function.
- Arcsine : arcsin. The arcsin function allows the calculation of the arc sine of a number. The arcsin function is the inverse function of the sine function.
- Arctangent : arctan. The arctan function allows the calculation of the arctan of a number. The arctan function is the inverse functions of the tangent function.
- Trigonometric Calculator : simplify_trig. Calculator wich uses trigonometric formula to simplify trigonometric expression.
- Cosine : cos. The cos trigonometric function calculates the cos of an angle in radians, degrees or gradians.
- Cosecant : cosec. The trigonometric function sec allows to calculate the secant of an angle expressed in radians, degrees, or grades.
- Cotangent : cotan. The cotan trigonometric function to calculate the cotan of an angle in radians, degrees or gradians.
- Trigonometric expansion : expand_trigo. The calculator makes it possible to obtain the trigonometric expansion of an expression.
- Trigonometric linearization : linearization_trigo. Calculator that allows to linearize a trigonometric expression.
- Simplify Calculator : simplify. Calculator wich can simplify an algebraic expression online.
- Secant : sec. The trigonometric function sec allows to calculate the secant of an angle expressed in radians, degrees, or grades.
- Sine : sin. The sin trigonometric function to calculate the sin of an angle in radians, degrees or gradians.
- Tangent : tan. The tan trigonometric function to calculate the tan of an angle in radians, degrees or gradians.
- Calculation of the monthly payments of the insurance of a credit : loan_insurance. Credit insurance monthly payment calculator: real estate credit, consumer credit, and other types of credit.
- Algebra calculator : calculator. Calculator that allows to make algebraic calculation by combining operations with letters and numbers, and to indicate the steps of calculation.
- Simplifying surds calculator : simplify_surd. Online surds calculator that allows you to make calculations in exact form with square roots: sum, product, difference, ratio.
- List of calculations applicable to an algebraic expression : see_possible_calculations. Return the list of calculations that can be done on an algebraic expression.
- Calculation of binomial coefficients : binomial_coefficient. A binomial coefficient calculator that allows you to calculate a binomial coefficient from two integers.
- Partial fraction decomposition calculator : partial_fraction_decomposition. The calculator allows a rational fraction to be broken down into simple elements.
- Derivative calculator : derivative. The derivative calculator allows steps by steps calculation of the derivative of a function with respect to a variable.
- Taylor expansion calculator : taylor_series_expansion. The taylor series calculator allows to calculate the Taylor expansion of a function.
- Logarithmic expansion : expand_log. The calculator makes it possible to obtain the logarithmic expansion of an expression.
- Expand calculator : expand. Calculator is able to expand an algebraic expression online and remove unnecessary brackets.
- Expand and simplify an algebraic expression online : expand_and_simplify. Online calculator that allows you to expand and reduce an algebraic expression.
- Factoring calculator : factor. The factoring calculator allows to factor an algebraic expression online with steps.
- Solved mathematical exercises generator : exercise_generator. Returns a list of mathematical exercise statements and their solutions that can be used by teachers to prepare tests and quizzes.
- Integral calculator : integral. The integral calculator calculates online the integral of a function between two values, the result is given in exact or approximated form.
- Indefinite integral calculator : antiderivative. The antiderivative calculator allows to calculate an antiderivative online with detail and calculation steps.
- Limit calculator : limit. The limit calculator allows the calculation of the limit of a function with the detail and the calculation steps.
- Calculation of the monthly payments of a loan : monthly_loan. Loan monthly payment calculator : home loan, consumer loan, and other types of loan.
- Scientific online calculator : evaluate. Online Scientific Calculator to calculate algebraic expressions and get a numerical result.