
Jay T. answered 03/10/23
Retired Engineer/Math Tutor
Use u-substitution.
Let u=√x.
du = 1/2√xdx
dx = 2√xdu
Translate the integration limits from x-space to u-space.
Lower limit for u is √0 = 0
Upper limit for u is √1 = 1
So, translating the integral from x-space to u-space:
∫o1 sec(√x)/√x dx -> ∫o1 sec(u)/√x (2√xdu)
= 2 ∫o1 sec(u)du
= 2 ln(sec(u) + tan(u))01
= 2 (ln(sec(1)+tan(1))-ln(sec(0)+tan(0)))
≈ 2 (ln(1.851+1.557)-ln(1+0)))
≈ 2 (ln(3.408)+ln(1))
≈ 2 (1.226 + 0)
≈ 2.452