- A.0
- B.1
- C.-1
- D.<img src="//img1.yqda.net/question-name/ee/8726e6379aa129fe7985500fa5c81d.jpg" height="24" width="29" />
- A.π
- B.∞
- C.2π
- D.<img src="//img1.yqda.net/question-name/8e/7970756f8174b6d36e179ac3b2b6d1.jpg" height="31" width="52" />
- 18
-
( )
- A.Y轴对称
- B.直线y=x对称
- C.原点对称
- D.x轴对称
- 19
-
有()
- A.f(x)=-g(x)
- B.f(x)+g(x)=1
- C.f(x)=g(x)
- D.f(x)=g(x)+c(C为任意常数)
- 20
-
下列函数为初等函数的是
- A.cosx
- B.-sinx
- C.<img src="//img1.yqda.net/question-name/db/c133b69612077aa343281332ac6e82.jpg" height="29" width="28" />
- D.<img src="//img1.yqda.net/question-name/0b/d4c68e105eb98144557ade8c3d1e5f.jpg" height="30" width="30" />
- A.cosx
- B.-sinx
- C.<img src="//img1.yqda.net/question-name/db/c133b69612077aa343281332ac6e82.jpg" height="29" width="28" />
- D.<img src="//img1.yqda.net/question-name/0b/d4c68e105eb98144557ade8c3d1e5f.jpg" height="30" width="30" />
- 24
-
( )