Question 1040389
f(x)= 0.41 ln(x+1) +28
f(0)=0.41* ln(1)+28, because x+1=1.
ln(1)=0
Therefore f(0)=28
f(100)=0.41*ln(101)+28
ln(101)=4.615
Without rounding yet, multiply that by 0.41, then add 28.  Then round
The first part is 1.892, and the answer is 29.892 to three places.
f(x)=31
31=0.41*ln(x+1)+28.  Subtract 28 from both sides
3=0.41*ln(x+1), divide both sides by 0.41
7.317=ln(x+1).  Don't round.  Now, raise both sides to the e power.  e ^ ln (x+1)=x=1 by definition.
e^7.37=x+1
1505.79=x+1
to the nearest day, x=1504.79 or 1505 days
---------
Check
0.41 ln (1506)+28; ln (1506)=7.317
7.317(0.41)=3.000
3+28=31
{{{graph(300,200,-10,1500,-5,40,0.41*ln(x+1)+28)}}}