How do you find the derivative of #G(x)=int (e^(t^2))dt# from #[1,x^2]#?

1 Answer
Nov 3, 2017

The Fundamental Theorem of Calculus states that, if #y(x)=int_a^xf(t)\ dt#, then #dy/dx=f(x)#.

The problem gives a function #G(x)# defined as #int_1^(x^2)e^(t^2)\ dt#.

Since the bound is #x^2#, if we apply the Fundamental Theorem, we get #(dG)/(d(x^2))=e^(x^2)#. However, we want to know what #(dG)/dx# is.

To do this, we apply the chain rule. Given #(dG)/(d(x^2))#, if we multiply this by #(d(x^2))/dx#, we get #(dG)/cancel(d(x^2))*cancel(d(x^2))/dx=(dG)/dx#.

Using the power rule, #(d(x^2))/dx=2x#.

Thus, #(dG)/dx=(dG)/(d(x^2))*(d(x^2))/dx=2xe^(x^2)#