Math Gr12 Advanced Functions
posted by Billy Bob .
I am stuck on this one part of this question:
The function S(d)=93(logd)+65 relates the speed of the wind S, in miles per hours, near the centre of a tornado to the distance that the tornado travels,d,in miles. If a tornado has sustained winds of about 250 mph, estimate the distance it can travel.
I do this :
250= 93logd +65
185/93= logd
logd= 0.989247312
I don't know what to do after that because I cannot divide anything by log. Or is there some other way I should be doing this?

You have to take the inverse of log, that is ...
what number d you you need, so that log d = .989...
BTW, I got log d = 1.9892....
hope yours was just a typo.
On most calculators, use the 2ndF key
on mine, I would press the following:
2ndF
log
1.98924..
=
to get 97.5545
Without having to reenter the 1.98...
Here is the sequence of my keystrokes
250

65
=
÷
93
=
2ndF
log
=
to get the 97.5545
Respond to this Question
Similar Questions

advanced functions HELP!!!
the function S(d)=93logd+65 relates the speed of the wind, S, in mile per hour, near the centre of a tornado to the distance that the tornado travels, d, in miles. a)Calculate the avg. rate of change for the speed of the wind at the … 
math
A certain aircraft can fly 768 miles with the wind in 4 hours and travel the same distance against the wind in 6 hours. what is the speed of the wind? 
science
Which of the following is the MOST destructive force associated with tornadoes? 
repost math question
An aircraft flew 6 hours with the wind. The return trip took 7 hours against the wind. If the speed of the plane in still air is 276 miles per hour more than the speed of the wind, find the wind speed and the speed of the plane in … 
physics
A tornado lifts a car to a height of 125m above the ground. The tornado flings the car horizontally with a speed of 90.0 m/s. How long does the car take to reach the ground? 
Science
Can you tell me one time a tornado actually took place in the world and which tornado was it? 
algebra
An airplane flying with the wind can cover a certain distance in a = 3 hours. The return trip against the wind takes b = 4.5 hours. How fast is the plane and what is the speed of the wind, if the oneway distance is c = 720 miles? 
Physics
A very large electric current can flow inside a tornado from the clouds to the ground. If the magnetic field is measured to be 1.62×108 T at a distance of 8.33 km from the tornado, then what is the magnitude of this current? 
Math
an aircraft flew 2 hours with the wind. the return trip took 3 hours against the wind. if the speed of the plane in still air is 140 miles per hour more than the speed of the wind, find the wind speed and the speed of the plane in … 
Math
As a tornado moves, its speed increases. The functions S(d) = 93logd+65 relates the speed of the wind, S, in miles per hour, near the center of a tornado to the distance that the tornado has traveled,d, in miles. a) Graph this function. …