- A.0
- B.1
- C.3
- D.3!
- A.y=sinx+cosx
- B.<img src="//img1.yqda.net/question-name/5e/b98913941851e141395222549b801c.jpg" height="30" width="61" />
- C.<img src="//img1.yqda.net/question-name/a4/5fa6dd4dff4e5f83624989dddcfa80.jpg" height="29" width="94" />
- D.<img src="//img1.yqda.net/question-name/6a/c8d6f54502c83732588c2b295d1839.jpg" height="30" width="128" />