Question

Determine each function as even, odd, or neither. Prove it!
(#21) f(x)= sinx
(22.) f(x)=cos2x
(23.) f(x)= sec x
(24.)f(x)=x^3+1
(25.)f(x)=3sq. root 2x
(26.)f(x)=x^3+2x

Answer 1

sinx is even, because sin(pi/2)= 1 and sin(-pi/2)=-1

Answer 2

sinx is odd

Answer 3

i think you might have the definitions mixed up. a function is even if:
\[f(-x) = f(x)\] and odd if:
\[f(-x) = -f(x)\]

sin(x) is odd because:
\[s(-x) = -\sin(x)\]

Answer 4

cos 2x should be even

Answer 5

secx even

Answer 6

3sqrt(2x) can't be negative so maybe not even and not odd

Answer 7

rest should be odd

Answer 8

x^3+1 is neither.

x^3 by itself is odd, the +1 throws things off.

Answer 9

Yes thanks Joe................... I forgot the 1 effect lol