if $1000 is invested at an interest rate,r, compunded annually, the amount in the account after 4 years is given by the polynomial function A(r)= 1000(1+r)^4. Graph this function in an approriate window. describe the how this function is transformed from graph f(r)=r^4. at what interest rate would the money need to be invested in order to yield $1200 after 4 years?