Question Detail
Question
The Maclaurin series expansion of cosh(x) is
Correct Answer
Option A is the correct answer.
Detailed Explanation
cosh x is the sum of ½(eˣ+e⁻ˣ), and its Maclaurin series is the even-power terms of eˣ's series with all positive signs: 1+x²/2!+x⁴/4!+x⁶/6!+...
Hint
cosh x is closely related to cos x's series but without the alternating signs.