Now I see three is the answer.......when folded as a solid...I think this is the path to take:
Sorry...... I didn't read the question very carefully !
When x = 0 (year 0 ) 720500 represents the starting population
1.022 is the growth factor 1+.022 means 2.2 % growth/year
1548800 = 720500 1.022^x
log(2.1496) = log 1.022 * x
x = 35.17 years
1980 + 35.17 = 2015
Similarly.....treat 2,1 as a vector slope = rise/run = 1/2 orthoganal slope is -2
-3,6 rise / run = 6/-3 = -2 orthogonal
1,2 2/1 = 2 nope
-2,-3 -3/-2 nope
1, -2 -2/1 orthogonal
y = 2^(5-8x) solve for x
log y = log 2 * (5-8x)
log y / log 2 = 5-8x
5 - logy/log2 = 8x
5/8 - 1/8 logy/log2 = x now swithch the x and y's
5/8 - 1/8 log x / log 2 = f^-1(x)
5/8 - .41524 log x
Deleted.................
10 (million) = ,5 * 1.21^(x/2) divide both sides by .5
20 = 1.21^(x/2) Take LOG of both sides
log 20 = x/2 Log 1.21 divide by log 1.21
15.716 = x/2 mult both sides by 2
x =31.43 years
1988 + 31.43 years = 2019
Yeppers..... keep going......you can do it....fewer choices now available makes it easier.
https://web2.0calc.com/questions/help_66955
Ya-a-a-a-h CPhill gave you that one Haha..... keep going ! He gave you the second one too....
