tanα=3/5,α为锐角,求 (4cosα-5sinα)/(2cosα+3sinα)

来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/15 05:46:51
tanα=3/5,α为锐角,求(4cosα-5sinα)/(2cosα+3sinα)tanα=3/5,α为锐角,求(4cosα-5sinα)/(2cosα+3sinα)tanα=3/5,α为锐角,求(

tanα=3/5,α为锐角,求 (4cosα-5sinα)/(2cosα+3sinα)
tanα=3/5,α为锐角,求 (4cosα-5sinα)/(2cosα+3sinα)

tanα=3/5,α为锐角,求 (4cosα-5sinα)/(2cosα+3sinα)
sinα/cosα=tanα=3/5
sinα=(3/5)cosα
原式=(4cosα-3cosα)/[2cosα+(9/5)cosα]=5/19

(4cosα-5sinα)/(2cosα+3sinα)=(4-5tanα)/(2+3tanα)=1/(19/5)=5/19