For a positive number \(a\), let \[I(a) = \int_0^a \! \left(4 - 2^{x^2} \right) \, dx.\]
Then \(\dfrac{dI}{da}=0\) when \(a\) equals
\(\dfrac{1 + \sqrt{5}}{2}\),
\(\sqrt{2}\),
\(\dfrac{\sqrt{5} - 1}{2}\),
\(1\).
For a positive number \(a\), let \[I(a) = \int_0^a \! \left(4 - 2^{x^2} \right) \, dx.\]
Then \(\dfrac{dI}{da}=0\) when \(a\) equals
\(\dfrac{1 + \sqrt{5}}{2}\),
\(\sqrt{2}\),
\(\dfrac{\sqrt{5} - 1}{2}\),
\(1\).