x2 |
2 |
x3 |
3 |
x4 |
4 |
x2012 |
2012 |
x2013 |
2013 |
1+x2013 |
1+x |
在區(qū)間[-3,3]上,
1+x2013 |
1+x |
由于g(-3)式子中右邊x的指數(shù)為偶次項(xiàng)前為負(fù),奇數(shù)項(xiàng)前為正,結(jié)果必負(fù),即g(-3)<0,
且g(3)=1+3+(-
x2 |
2 |
x3 |
3 |
x4 |
4 |
x5 |
5 |
x2012 |
2012 |
x2013 |
2013 |
故在[-3,3]上函數(shù)g(x)有且只有一個(gè)零點(diǎn).
又y=cos2x在區(qū)間[-3,3]上有四個(gè)零點(diǎn),且與上述零點(diǎn)不重復(fù),
∴函數(shù)f(x)=(1+x-
x2 |
2 |
x3 |
3 |
x4 |
4 |
x2012 |
2012 |
x2013 |
2013 |
故選C.