has to be positive for all x
has to be an even function, same + or -
so
2 x^2
for which of following functions is graphof y = |f(x)| identical to graph of y = f(x)?
A. f(x) = 2x
B. f(x) = -2x
C. f(x) = 2x^2
D. f(x) = -2x^2
i real not get this.
3 answers
ok can u explain to me again that i still not get it.
|f(x)| is positive, but
2x can be negative
-2x can be negative
x^2 is always positive, so
-2x^2 is always negative.
The only choice which is always positive is 2x^2
so, |2x^2| = 2x^2
2x can be negative
-2x can be negative
x^2 is always positive, so
-2x^2 is always negative.
The only choice which is always positive is 2x^2
so, |2x^2| = 2x^2