All electronic devices would not exist without calculus.
Engineers would be able to do nothing without calculus, which means everything that we have that we owe to engineers, we owe to calculus as well.
Physics would not exist beyond the high school level (which is trigonometry based) without calculus. If you asked this question to help you with a school assignment, here's a good common saying you can use: Calculus is the language of physics.
Applied chemistry requires calculus, which means that everything that we owe to applied chemistry, we also owe to calculus.
Chat with our AI personalities
It is the study of how to apply calculus to functions of more then 1 variable. It allows us to do the same things we could in two dementions in n dementions. It is closely related to linear algebra.
I am assuming you understand the distinction between single-variable calculus (calculus of one variable) and multivariable calculus (calculus of several variables). Well, if you know the former, that is highly beneficial because the same techniques are used in the latter -- they are generalized to apply to calculus of n-variables. This is ultimately the goal of single-variable calculus. Why? Well, if you think about it, single-variable is not really applicable. Not many real world phenomena involve one variable. For example, in macroeconomics, GDP = Y is a function of many variables: Consumption (a function of net taxes and income), Investment (a function of real interest rates), Government Spending, and Net Exports. That is, Y=f(C(Y,T), I(r), G, NX). To perform many of the tools of calculus (e.g. finding how Y changes as G increases) to this function, one must know and apply multivariable calculus.
Calculus; by a long shot.
Just about all of calculus is based on differential and integral calculus, including Calculus 1! However, Calculus 1 is more likely to cover differential calculus, with integral calculus soon after. So there really isn't a right answer for this question.
It is certainly used in calculus, just as calculus can be used in trigonometry.