Question 766504: two variable quantities x and y are related by equation y=a(b^x),whwre a and b are constant.When the graph is plotted showing values of ln y in vertical axis and the value of x on the horizontal axis the points lie on a straight line having gradient 1.8 and crossing the vertical axis at the point (0.4.1).Find the value of a and b
Answer by josgarithmetic(39618) (Show Source):
You can put this solution on YOUR website! You are saying, apparantly, the included point is the vertical axis intercept at (0, 0.41) or is it (0, 4.1)?
and taking natural log both sides gives a linear equation:
______ a linear equation, vertical intercept ln(a) and slope ln(b).
Finding b is not a problem. Finding a, maybe a little problem, depending on vertical intercept.
so
The vertical intercept is for x=0, so you have this:

Either Or depending on which you really have. Find a from the proper one.
If vertical intercept 0.41, then 
......OR
If vertical intercept 4.1, then
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