Wednesday

August 20, 2014

August 20, 2014

Posted by **Jus** on Sunday, May 17, 2009 at 7:14pm.

a) write an equation that expresses the amount, A, of the investment as a function of time, t, in years.

b) determine how long it will take for this investment to double in value and then to triple in value.

c) determine the percent increase in value of the account after 5 years and then after 10 years.

d) explain why the answers to parts b and c do not depend on the amount of the initial principal.

Can someone explain to me how to get started? I do not know where to start except for the fact that I need to make an exponential function.

- exponential function -
**Damon**, Sunday, May 17, 2009 at 7:56pmafter one year

A = Ao (1.08)

after two years

A = Ao (1.08)(1.08)

after three years

A = Ao (1.08)(1.08)(1.08)

after t years

A = Ao (1.08)^t

When is A/Ao = 2?

2 = 1.08^t

log 2 = t log 1.08

.301 = t * .0334

t = 9.01 years to double

That should get you started.

- exponential function -
**Jus**, Sunday, May 17, 2009 at 8:04pmdid i do part c right?

c) determine the percent increase in value of the account after:

5 years,

A=(1.08)^5

=1.47

therefore 1.47 % increase???

- exponential function -
**Jus**, Sunday, May 17, 2009 at 8:09pmc) continued:

after 10 years

A=(1.08)^10

=2.16

therefore 2.16% increase?

Am I doing this right?

d) Explain why the answers to parts b and c do not depend on the amount of the initial principal.

- exponential function -
**Damon**, Sunday, May 17, 2009 at 8:12pm" =1.47

therefore 1.47 % increase??? "

A factor of 1.47 is a 47% increase

100 * final/original = 147/1 =147 %

which is 47 % over the original 100%

- exponential function -
**Damon**, Sunday, May 17, 2009 at 8:13pm2.16 * 100 = 216 % of original

216 % - original 100% = 116% increase

**Related Questions**

Exponential Word Problem - An investment pays 3.5 percent interest, compounded ...

advanced functions - An investment pays 8% interest, compounded annualy. Write ...

Algebra - Greta invests $10,000 in an investment that pays 3% interest, ...

Maths B - Kate is thinking about investing $45000 for 5 years. She deposits her ...

Investment interest - Scenario: A client comes to you for investment advice on ...

math/ compounded - Scenario: A client comes to you for investment advice on his...

math - A client comes to you for investment advice on his $500,000 winnings ...

math - A client comes to you for investment advice on his $500,000 winnings ...

pre calculus - Which is worth more after 5 years, an investment of $1000 at 5% ...

compound interest - How do I solve these problems? Complete the table for a ...