Question

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..

Answer 1

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.

Answer 2

d^2 = 17^2 = 289
289 = 8^2 + (2-a)^2
289 = 64 + 4 - 4a + a^2
a^2 - 4 a -221 = 0
(a-17)(t+13) = 0
a = 17 or a = -13

Answer 3

Thank you very much, I was beyond stumped.