Find a formula for the described function.

Question

Find a formula for the described function.

A rectangle has area 16 m². Express the perimeter of the rectangle as a function of the length L of one of its sides.

P(L) = 

 

State the domain of P. (Assume the length of the rectangle is larger than its width. Enter your answer using interval notation.)

Answer 1

(L)(W) = 16

W = 16/L

P(L) = 2(L + W)

P(L) = 2(L + 16/L)

P(L) = 2L + (32/L)

Answer 2

P=2L + 2W

W=(P/2)-L

P[(P/2)-L}=16

P²-2LP-32=0

Use the quadratic formula to express P as a function of L.