求X,x is in radians1）sin^2x- cosx =12）2sin^2-tanxcosx-1 =0_数学解答

求X,x is in radians
1）sin^2x- cosx =1
2）2sin^2-tanxcosx-1 =0

人气：202 ℃　时间：2020-05-26 15:37:25

解答

1）sin²x- cosx =11-cos²x-cosx=1cosx(cosx+1)=0cosx=0,cosx=-1x=kπ+π/2,x=2kπ+π2）2sin²x-tanxcosx-1 =0 2sin²x-(sinx/cosx)cosx-1=02sin²x-sinx-1=0(2sinx+1)(sinx-1)=0sinx=-1/2,si...