x = 7 and x = –7.
Solution:
Given data:
[tex]$f(x)=x^{2}+15[/tex] and [tex]f(x)=64[/tex]
To find the solutions when f(x) = 64.
Both are equations of f(x), so equate the given equations, we get
[tex]x^2+15=64[/tex]
To isolate the constant term subtract 15 from both sides.
[tex]x^2+15-15=64-15[/tex]
[tex]x^2=49[/tex]
49 can be written as 7².
[tex]x^2=7^2[/tex]
Taking square root on both sides of the equation, we get
x = ±7
The solutions to f(x) = 64 is x = 7 and x = –7.
