Question

How do you use the second fundamental theorem of Calculus to find the derivative of given `int tan(t) dt` from `[1, x]`?

Answer 1

See below

Explanation:

the FTC tells us that

`d/dx int_a^x f(t) \ dt = f(x)`

We can apply that directly here as:
`d/dx int_1^x tan(t) \ dt = tan(x)`