A: w(x) = x^4 + x^2 - 1 is an even function.
B: k(x) = (ln x)^2 is an even function.
a. Only A is true.
b. Only B is true.
c. Both A and B are true.
d. Both A and B are false.
2006-12-03 04:26:04 · 3 answers · asked by chris 2 in Science & Mathematics ➔ Mathematics
a function is even iff f(x)=f(-x)
in a f(x)=f(-x) hence true...
but in B f(x) or f(-x) is not defined as logarithm of a negative number to base e is not defined...
hence only a is true
2006-12-03 04:36:15 · answer #1 · answered by indurti karthik 2 · 0⤊ 0⤋
Even function:
f(x) = f(-x)
x^4+x^2-1 == (-x)^4+(-x)^2-1 (true)
(ln x)^2 == (ln (-x))^2 (false)
answer: a
2006-12-03 12:31:54 · answer #2 · answered by MooseBoys 6 · 0⤊ 0⤋
a is not true because even function means that it is symmetrical to the orgin and it is no
and i dont know what (ln x) is... but i just put x^2 and it is symmetrical to the orgin therefore B. only B is true
2006-12-03 12:31:55 · answer #3 · answered by angelwngs_00 2 · 0⤊ 0⤋