Question
Question: \[\frac{x^{2} - y^{2}}{1!} + \frac{x^{4} - y^{4}}{2!} + \frac{x^{6} - y^{6}}{3!} + ......\infty =\]...
1!x2−y2+2!x4−y4+3!x6−y6+......∞=
A
ex−ey
B
ex2−ey2
C
2+ex2−ey2
D
2ex−ey
Answer
ex2−ey2
Explanation
Solution
1⋅2!12+2⋅3!12+22+3⋅4!12+22+32+..+n⋅(n+1)!12+22+...+n2+...∞.