I find it convenient to express other trigonometric functions in terms of sine and cosine - that tends to simplify things. The secant function is even because it is the reciprocal of the cosine function, which is even. The tangent function is the sine divided by the cosine - an odd function divided by an even function. Therefore it is odd. The cosecant is the reciprocal of an odd function, so it is naturally also an odd function.
Odd. Even + Even = Even Odd + Odd = Even Odd + Even = Even + Odd = Odd
odd * odd = odd answer even * even = even answer odd * even = even answer
Yes. Even + Even = Even, Odd + Odd = Even and Even + Odd or Odd + Even = Odd
even times even = even odd times odd = odd even times odd = even
It is an odd function. Even functions use the y-axis like a mirror, and odd functions have half-circle rotational symmetry.
yes
An even function is symmetric about the y-axis. An odd function is anti-symmetric.
Probably because polynomials and convergent power series in which all terms have even degree are even functions, and similarly for odd.
Basically, a knowledge of even and odd functions can simplify certain calculations. One place where they frequently appear is when using trigonometric functions - for example, the sine function is odd, while the cosine function is even.
I find it convenient to express other trigonometric functions in terms of sine and cosine - that tends to simplify things. The secant function is even because it is the reciprocal of the cosine function, which is even. The tangent function is the sine divided by the cosine - an odd function divided by an even function. Therefore it is odd. The cosecant is the reciprocal of an odd function, so it is naturally also an odd function.
Yes. Along with the tangent function, sine is an odd function. Cosine, however, is an even function.
Odd. Even + Even = Even Odd + Odd = Even Odd + Even = Even + Odd = Odd
Best example is that an "odd" (or "even") function's Maclaurin series only has terms with odd (or even) powers. cos(x) and sin(x) are examples of odd and even functions with easy to calculate Maclaurin series.
odd * odd = odd answer even * even = even answer odd * even = even answer
even times even = even odd times even = even odd times odd = odd
Yes. Even + Even = Even, Odd + Odd = Even and Even + Odd or Odd + Even = Odd