Answer:
(a) These are the same function
Step-by-step explanation:
Given
[tex]x + x^2[/tex] and [tex]u + u^2[/tex]
Required
Are they the same?
Yes, they are the same function and this is proved below.
[tex]x + x^2[/tex]
Represent as a function:
[tex]f(x) = x + x^2[/tex]
[tex]u + u^2[/tex]
Represent as a function
[tex]f(u) = u + u^2[/tex]
Let x = u
Substitute u for x in [tex]f(x) = x + x^2[/tex]
[tex]f(u) = u + u^2[/tex]
This implies that:
[tex]f(x) = f(u)[/tex]
[tex]x + x^2 =u + u^2[/tex]
PS: The information that x and u are real numbers are for all real numbers; So, we can not assume that x and u are different numbers
Hence:
(b) and (c) are wrong