Algebra
posted by Lyn on .
I can not figure these out for the life of me. Any help is appreciated.
1. Find the final amount of an investment if $2,000 is invested at an interest rate of 8% compounded quarterly for 8 years.
I used interest formula and came up with $1,769.08.
And then:
I = .08/4 = .02
N = 8(4) = 32
Amount= 2,000(.02)^32
= 8.59 ?
And then:
2000(1+0.08/4)^4 = 2164.86
2. Find the possible values for a, if the distance between the points is 17 and the coordinates of the points are (4, a) and (4, 2)
D= √(4  (4))^2 + (2  a)^2
I used the distance formula and it came out as an imaginary number..

I = .08/4 = .02
N = 8(4) = 32
Amount= 2,000(.02)^32 ****NO****
Amount = 2,000(1.02)^32
= 3769.08
If you add 2% at every stage you multiply by 1.02 at every stage. 
d^2 = 17^2 = 289
289 = 8^2 + (2a)^2
289 = 64 + 4  4a + a^2
a^2  4 a 221 = 0
(a17)(t+13) = 0
a = 17 or a = 13 
Thank you very much, I was beyond stumped.