1、
tana=2tan(a/2)/[1-tan²(a/2)]=-4/3
所以tan(a+π/4)
=(tana+tanπ/4)/(1-tanatanπ/4)
=(-4/3+1)/{1+4/3)
=-1/7
2
原式分子分母同除以cosa
由sina/cosa=tana
原式=(3tana-2)/(6tana+1)
=(-4-2)/(-8+1)
=6/7
已知tan2/a=2,求:(1) tan(a+4/π) ; (2)3sina-2cosa/6sina+cosa,
已知tan2/a=2,求:(1) tan(a+4/π) ; (2)3sina-2cosa/6sina+cosa,
数学人气:166 ℃时间:2020-02-04 05:41:19
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