Seasons in the Sun - Westlife
Verse 1:
Now that spring is here
The days are getting longer
You're leaving me behind
And it doesn't feel like anything
Chorus:
It's hard to say goodbye
To all the memories we made
But I know you'll come back to me
Someday when the seasons change
Verse 2:
You take my hand and say goodbye
And I can't stop my tears from falling
I try to hide my pain
But I know you'll always be a part of me
Chorus:
It's hard to say goodbye
To all the memories we made
But I know you'll come back to me
Someday when the seasons change
Bridge:
I'll be here waiting for you
When the days are cold and lonely
I'll be here waiting for you
Until you come back home again
Chorus:
It's hard to say goodbye
To all the memories we made
But I know you'll come back to me
Someday when the seasons change (x2)
Outro:
I know it's hard for you to leave me now
But remember, I'll always love you請問這道題怎么做？請給出詳細步驟，謝謝！已知函式f(x) = x^3 - 3x^2 + 9x - 18，求f(x)的單調區間。
解：函式$f(x) = x^{3} - 3x^{2} + 9x - 18$的導數為$f^{\prime}(x) = 3x^{2} - 6x + 9$，令$f^{\prime}(x) > 0$，解得$x < 1$或$x > 3$；令$f^{\prime}(x) < 0$，解得$1 < x < 3$．故函式$f(x)$在$( - \infty ，1)$上單調遞增，在$(1，3)$上單調遞減，在$(3， + \infty)$上單調遞增．因此函式$f(x)$的單調遞增區間為$( - \infty ，1)$和$(3， + \infty)$，單調遞減區間為$(1，3)$．