Let a differentiable function f satisfy the equation ∫036f(tx36)dt=4αf(x). If y=f(x) is a standard parabola passing through the points (2, 1) and (-4,β), then βα is equal to _____. [2026]
(64)
∫036f(tx36)dt=4αf(x), Put tx36=y
dydt=x36
∫0xf(y)36dyx=4αf(x)
∫0xf(y)dy=αf(x)x9
f(x)=α9(f(x)+xf'(x))
(1-α9)f(x)=αx9f'(x)⇒(9-α)f(x)=αxf'(x)
f'(x)f(x)=(9α-1)1x
logef(x)=(9α-1)logex+logec
f(x)=cx(9α-1) For standard parabola,
9α-1=2
α=3
f(x)=cx2
Passing through (2,1)
1=4c⇒c=14
y=x24 passing through (-4,β)
β=4
βx=43=64