Let (11–a+21+a),f(a),(3a+3–a), f(a), be in A.P. and α be the minimum value of f(a). Then the value of the integral ∫loge(α–1)loge(α)dx(e2x–e–2x) is: [2026]
(2)
Given, (11–a+21+a),f(a),(3a+3–a) are in A.P., then
f(a)=3a+13a+2(2a+12a)2
f(a)min=3 at a=0
So, α=3
Let I=∫ln2ln3dxe2x–e–2x
Put e2x=t
⇒ 2e2xdx=dt
I=12∫49dtt2–1=14(ln45–ln35)=14(ln43)