新高考数学一轮复习计算题精练专题09 三角恒等变换（解析版）

三角恒等变换1．SKIPIF1<0（

）A．SKIPIF1<0 B．SKIPIF1<0 C．SKIPIF1<0 D．SKIPIF1<0【答案】A【详解】SKIPIF1<0SKIPIF1<0SKIPIF1<0SKIPIF1<0．故选：A．2．sin40°cos10°+cos140°sin10°＝（

）A．﹣SKIPIF1<0 B．SKIPIF1<0 C．﹣SKIPIF1<0 D．SKIPIF1<0【答案】D【详解】sin40°cos10°+cos140°sin10°，=sin40°cos10°-cos40°sin10°，=sin（40°-10°），=sin30°＝SKIPIF1<0.故选：D3．SKIPIF1<0A．SKIPIF1<0 B．SKIPIF1<0 C．SKIPIF1<0 D．SKIPIF1<0【答案】B【详解】SKIPIF1<0故选B4．已知SKIPIF1<0，则SKIPIF1<0（

）A．SKIPIF1<0 B．SKIPIF1<0 C．SKIPIF1<0 D．SKIPIF1<0【答案】A【详解】因为SKIPIF1<0，故SKIPIF1<0，故选：A5．若SKIPIF1<0，则SKIPIF1<0（

）A．SKIPIF1<0 B．SKIPIF1<0 C．SKIPIF1<0 D．SKIPIF1<0【答案】D【详解】因为SKIPIF1<0，所以SKIPIF1<0，即SKIPIF1<0，所以SKIPIF1<0，即SKIPIF1<0，所以SKIPIF1<0，故选：D．6．SKIPIF1<0（

）A．SKIPIF1<0 B．SKIPIF1<0 C．SKIPIF1<0 D．SKIPIF1<0【答案】A【详解】已知可化为：SKIPIF1<0.故选：A7．若SKIPIF1<0，则SKIPIF1<0（

）A．SKIPIF1<0 B．SKIPIF1<0 C．SKIPIF1<0 D．SKIPIF1<0【答案】D【详解】由SKIPIF1<0.故选：D8．已知SKIPIF1<0，且SKIPIF1<0，则SKIPIF1<0（

）A．SKIPIF1<0 B．SKIPIF1<0 C．SKIPIF1<0 D．1【答案】B【详解】SKIPIF1<0，SKIPIF1<0,SKIPIF1<0，又SKIPIF1<0，则SKIPIF1<0，即SKIPIF1<0所以SKIPIF1<0，因为SKIPIF1<0，所以SKIPIF1<0，SKIPIF1<0.由SKIPIF1<0平方可得SKIPIF1<0，即SKIPIF1<0，符合题意.综上，SKIPIF1<0.故选：B.9．已知SKIPIF1<0，则SKIPIF1<0（

）A．SKIPIF1<0 B．SKIPIF1<0 C．SKIPIF1<0 D．SKIPIF1<0【答案】C【详解】SKIPIF1<0，所以SKIPIF1<0，得SKIPIF1<0.故选：C.10．已知SKIPIF1<0，则SKIPIF1<0（

）A．SKIPIF1<0 B．SKIPIF1<0 C．2 D．4【答案】A【详解】因为SKIPIF1<0，所以SKIPIF1<0，故选：A.11．化简：SKIPIF1<0（

）A．SKIPIF1<0 B．SKIPIF1<0 C．SKIPIF1<0 D．SKIPIF1<0【答案】C【详解】根据题意可知，利用诱导公式可得SKIPIF1<0再由二倍角的正弦和余弦公式可得SKIPIF1<0，即SKIPIF1<0.故选：C12．SKIPIF1<0的值为（

）A．SKIPIF1<0 B．SKIPIF1<0 C．SKIPIF1<0 D．SKIPIF1<0【答案】A【详解】依题意由两角差的余弦公式可知，SKIPIF1<0.故选：A13．若SKIPIF1<0，则SKIPIF1<0____________【答案】SKIPIF1<0/-0.6【详解】SKIPIF1<0SKIPIF1<0，故答案为：SKIPIF1<014．已知SKIPIF1<0，且SKIPIF1<0，则SKIPIF1<0______．【答案】SKIPIF1<0【详解】SKIPIF1<0，SKIPIF1<0，SKIPIF1<0，SKIPIF1<0.SKIPIF1<0,SKIPIF1<0.故答案为：SKIPIF1<0.15．已知SKIPIF1<0，则SKIPIF1<0的值是______．【答案】SKIPIF1<0【详解】SKIPIF1<0SKIPIF1<0，故答案为：SKIPIF1<016．已知SKIPIF1<0，若SKIPIF1<0，则SKIPIF1<0_________.【答案】SKIPIF1<0【详解】因为SKIPIF1<0，SKIPIF1<0，所以SKIPIF1<0所以SKIPIF1<0所以SKIPIF1<0.故答案为：SKIPIF1<0.17．若SKIPIF1<0，则SKIPIF1<0________.【答案】SKIPIF1<0【详解】SKIPIF1<0SKIPIF1<0故答案为：SKIPIF1<018．已知SKIPIF1<0，SKIPIF1<0，则SKIPIF1<0_______________________．【答案】SKIPIF1<0【详解】因为SKIPIF1<0，所以SKIPIF1<0，由SKIPIF1<0可得SKIPIF1<0，整理可得SKIPIF1<0，SKIPIF1<0SKIPIF1<0．故答案为：SKIPIF1<019．若SKIPIF1<0，则SKIPIF1<0__________.【答案】SKIPIF1<0/SKIPIF1<0【详解】依题意，SKIPIF1<0，所以SKIPIF1<0，SKIPIF1<0，而SKIPIF1<0为锐角，所以SKIPIF1<0.故答案为：SKIPIF1<020．已知SKIPIF1<0，则SKIPIF1<0______．【答案】SKIPIF1<0【详解】SKIPIF1<0.故答案为：SKIPIF1<021．已知α是第二象限的角，SKIPIF1<0，则SKIPIF1<0________．【答案】SKIPIF1<0/SKIPIF1<0【详解】因为SKIPIF1<0，又α是第二象限的角，所以SKIPIF1<0，SKIPIF1<0，所以SKIPIF1<0.故答案为：SKIPIF1<0.22．已知SKIPIF1<0，则SKIPIF1<0______．【答案】SKIPIF1<0/0.5【详解】解：已知SKIPIF1<0，即SKIPIF1<0，解得SKIPIF1<0或SKIPIF1<0（舍），SKIPIF1<0，故答案为：SKIPIF1<0.23．若SKIPIF1<0，则SKIPIF1<0_________.【答案】SKIPIF1<0/SKIPIF1<0/SKIPIF1<0【详解】SKIPIF1<0SKIPIF1<0.故答案为：SKIPIF1<0.24．函数SKIPIF1<0的值域__________．【答案】SKIPIF1<0【详解】因为SKIPIF1<0，因为SKIPIF1<0，当SKIPIF1<0时，SKIPIF1<0取得最大值SKIPIF1<0，当SKIPIF1<0时，SKIPIF1<0取得最小值SKIPIF1<0，又因为SKIPIF1<0，所以SKIPIF1<0的值域为SKIPIF1<0．故答案为：SKIPIF1<0.25．已知SKIPIF1<0，SKIP