sin^2x+sinxcosx+2cos^2x
=(sin^2x+sinxcosx+2cos^2x)/(sin^2x+cos^2x)
=(tan^2x+tanx+2)/(tan^2x+1),【分子分母同除以cos^2x】
=(4+2+2)/(4+1)
=8/5
已知tanx=2 求sin^2x+sinxcosx+2cos^2x
已知tanx=2 求sin^2x+sinxcosx+2cos^2x
数学人气:830 ℃时间:2020-01-29 23:51:20
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