The function can be expressed as:
f(x) = log(-20x + 12√x)
To ascertain the maximum value, differentiate the equation with respect to x and set the derivative to zero. The procedure unfolds as follows.
The differentiation formula is:
d(log u)/dx = du/u ln(10)
Thus,
d/dx = (-20 + 6/√x)/(-20x + 12√x)(ln 10) = 0
-20 + 6/√x = 0
6/√x = 20
From which we derive x = (6/20)² = 9/100
Therefore,
f(x) = log(-20(9/100)+ 12√(9/100)) = 0.2553
The function's maximum value is 0.2553.
f(n) = -6.5n + 14.5
&
f(1) = 8, f(n+1) = f(n) - 6.5