Explanation:
a linear function is following
y = ax + b
that means the ratio of the y and x differences between the data points is constant (a).
an exponential function is in the form y = a^x. or some constant variations of it.
the base is constant (a), and the exponent of the constant is the variable (x).
1.
clearly exponential.
this is the typical graph of an exponential function.
it looks like y = 2^x, as e.g. f(4) = 2⁴ = 16, and the graph seems to be at least very close to this.
2.
exponential.
y = 3^(x - 0.5)
3¹ = 3
3² = 9
3³ = 27
3⁵ = 243
this is just y = 3^x shifted to the right by 0.5 units.
3.
linear.
the difference ratio between the data points is constant :
x is the row number (1, 2, 3, 4, 5, ...).
y is the number of seats per row (14, 16, 18, 20, 22, ...).
so,
(16-14)/(2-1) = 2/1 = 2
(18-16)/(3-2) = 2/1 = 2
...
(22-14)/(5-1) = 8/4 = 2
always constant (2).
4.
neither.
it is y = x²
when you compare 4. and 1. you see the clear difference between the 2 graphs.
5.
exponential.
remember, y = a^x.
well, here, a = 1/2. but that is still constant and doesnot change the principle.
the factor 10 stretches the graph a bit up (in fact, this 10 is the starting number of an exponential growth). but the function in its core is still exponential.
6.
linear.
when written that way, it just means that x = n, and for every increase of n by 1, y (f(n)) increases by +4.
so, the difference ratio stays constant (4/1 = 4).