Question

Find a polynomial function f(n) such that f(1), f(2), ... , f(8) is the following sequence.
4, 10, 16, 22, 28, 34, 40, 46

Answer 1

Its Discrete Math

Answer 2

I got 6n-4 but was not correct

Answer 3

looks it is a linear function.
let f(n) = an + b

when f(1) = 4, it means
a(1)+b = 4 or
a + b = 4 .... (1st equation)

and
f(2) = 10, it means a(2) + b = 10, or
2a + b = 10 ..... (2nd equation)

by elimination methode, subtract both equations get
a + b = 4
2a + b = 10
------------ (-)
-a = -6
a = 6

subtitute a = 6 into one of the equation above, let take 1st.
a+b = 4
6 + b = 4
b = 4 - 6
b = -2

see that f(n) = an + b. distribute the value of a and b to f(n), get
f(n) = 6n-2

Answer 4

Are you sure its 6n-2 tho?

Answer 5

we can cross-check, if f(n) = 6n -2 as the correct answer or not
f(n) = 6n - 2
check the values given above :
f(1) = 6(1) - 2 = 4 (true)
f(2) = 6(2) - 2 = 10 (true)
f(3) = 6(3) - 2 = 16 (true)
f(4) = 6(4) - 2 = 22 (true)
f(5) = 6(5) - 2 = 28 (true)
f(6) = 6(6) - 2 = 34 (true)
f(7) = 6(7) - 2 = 40 (true)
f(8) = 6(8) - 2 = 46 (true)

so, dont worry. that's right!

Answer 6

Okay okay thank you!

Answer 7

you're welcome ^_^