<p>barrons math 2c: to those who have the book
for the diagnostic test in the beggining
why is the answer D
for number 2.</p>
<p>to those who don't have the book question is</p>
<p>A function is said to be even if f(x) = f(-x). Which of the following is not an even function</p>
<p>a) y= lxl
b) y= sec x
c) y= logx
d) y= x2+sin x
e) y= 3x4+2x2+ 17</p>
<p>pleasee help</p>
<p>c I believe.</p>
<p>…i already told u the answer is D</p>
<p>im wondering why is D</p>
<p>…</p>
<p>yea…</p>
<p>HAHA sry i didnt read what you wrote.
I think because for d your y intercept is different.
instead of + something, you now have - something.</p>
<p>I dunno… I honestly thought it was c…</p>
<p>mm well in the barrons book it says
even functions are symmetric about the y-axis
so i tried to graph all those equations
but all of them were symmetric…(well i think?)</p>
<p>thanks for ur help, but i still don’t get it lol</p>
<p>a. it is an even function because plugging in both -x and x would be x.
b. it is an even function because plugging in both pi/2 and -pi/2 would be undefined
c. well, it is not an even function, and is not also an odd function, too
d. it is not an even function since it looks like a parabola, but shifted to the left y-axis
That’s all I got.</p>
<p>GAHHHHH, why are we talking about math?</p>
<p>Calculus test is already over!!!</p>
<p>bcuz a druda needs help!!!</p>
<p>lol thanks for trying guys
but i haven’t gotten a real explanation yet</p>
<p>still confused as a muda u know what</p>
<p>anyone?
this is driving me crazy
freaking barrons…</p>
<p>im off to sleep
it’ll hopefully be answered tommorow when i wake up</p>
<p>=D…0_0</p>
<p>Sometimes, you can look to see if it’s an even function by looking at the exponents. If all the exponents are even, it’s even. If all the exponents are odd, it’s odd. However, be careful. For example, f(x) = x^2 + x is not an even function, since it contains both an even exponent (2) and odd exponent (1).<br>
You must remember your trig functions as follows:
f(x) = sin x is an odd function
f(x) = cos x is an even function
f(x) = tan x is an odd function</p>
<p>so d is the answer because the sin x immediately tells us it’s not an even function?</p>
<p>anyone back that up?
or disagree with that?</p>
<p>the other thing that ****es me off is barrons explanation said u can graph all of them and the one that is not symmetrical about the y axis is the answer
i graphed em and they are ALL symmetrical (atleast i think)</p>
<p>also when we graph the answer choices, do we graph the answer choices or the negative form of the choices??</p>
<p>thanks</p>
<p>sin(pi/2)= 1
sin(-pi/2)= -1</p>
<p>thats why it’s D
although honestly i dont know why C cant be it either becuase negative logarithms do not exist</p>