Question

If the range of the function f(x) = 7x – 2.7 is {14.1, 30.9, 41.4, 58.9, 68}, what is its domain?

Answer 1

domain is {2.4, 4.8, 6.3, 8.8, 10.1 }

For domain, equate f(x) to each value in the range and solve for x

7x - 2.7 = 14.1 ⇒ x = $\frac{x14.1 + 2.7}{7}$ = 2.4

7x - 2.7 = 30.9 ⇒ x = $\frac{30.9 + 2.7}{7}$ = 4.8

7x - 2.7 = 41.4 ⇒ x = $\frac{41.4 + 2.7}{7}$ = 6.3

7x - 2.7 = 58.9 ⇒ x = $\frac{58.9 + 2.7}{7}$ = 8.8

7x - 2.7 = 68 ⇒ x = $\frac{68 + 2.7}{7}$ = 10.1