According to Wikipedia,
In mathematics, differential calculus is a subfield of calculus^{} concerned with the study of the rates at which quantities change. It is one of the two traditional divisions of calculus, the other being integral calculus, the study of the area beneath a curve.
Nickzom Calculator calculates function of a function for the following formats:

 (expression)^{n}
 k(expression)^{n}
 sin(expression)
 ksin(expression)
 cos(expression)
 kcos(expression)
 tan(expression)
 ktan(expression)
 sinh(expression)
 ksinh(expression)
 cosh(expression)
 kcosh(expression)
 cot(expression)
 kcot(expression)
 cosec(expression)
 kcosec(expression)
 In(expression)
 kIn(expression)
 log_{a}(expression)
 klog_{a}(expression)
 e^{(expression)}
 ke^{(expression)}
 a^{(expression)}
 ka^{(expression)}
k, a and n in the formats above represents constants.
The expression represents a polynomial, quadratic or linear mathematical statement, such as:
 3x + 5
 4x^{2} + 2x + 1
 2x^{3} + 7x + 12
 5x^{4} + 3x^{3} + 4x^{2} + 12x + 15
So implementing the expressions and applying constant numbers here is a list of what the function of a function formats look like that can be solved by Nickzom Calculator and also display the steps (workings).


 (2x^{2} + 3x + 5)^{7}
 4(2x + 1)^{6}
 sin(2x^{2} + 3x + 5)
 2sin(3x + 5)
 cos(3x + 5)
 2cos(3x + 5)
 tan(2x^{3} + 3x^{2} + 4x + 5)
 3tan(7x + 6)
 sinh(2x^{4} + 12)
 2sinh(3x + 10)
 cosh(x^{5} + 2x^{3} + 11)
 3cosh(2x^{3} + 12x + 17)
 cot(2x + 1)
 3cot(3x + 5)
 cosec(x + 12)
 7cosec(2x + 7)
 In(x^{3} + 2x + 7)
 2In(2x^{2} + 3x + 12)
 log_{3}(3x + 7)
 2log_{2}(x^{2} + 4x + 8)
 e^{(3x + 5)}
 2e^{(2x + 3)}
 2^{(7x + 2)}
 7 . 2^{(6x + 7)}
