To make complex mathematical calculations using trigonometric functions, use an engineering calculator. All commands are entered using the keyboard or mouse. To calculate the cotangent, tangent, cosine and sine of the angle, you can now use this type of calculator. In addition, it can be used to calculate the logarithm of a number, as well as to raise a number to a power.To make complex mathematical calculations using trigonometric functions, use an engineering calculator. All commands are entered using the keyboard or mouse. To calculate the cotangent, tangent, cosine and sine of the angle, you can now use this type of calculator. In addition, it can be used to calculate the logarithm of a number, as well as to raise a number to a power.