已知函数f(x)=-1+2根号3sinxcosx+2cos2x.

2个回答

  • f(x)=-1+2根号3sinxcosx+2cos2x

    =√3sin2x+cos2x

    =2sin(2x+π/6)

    1.单增区间为2x+π/6∈[2kπ-π/2,2kπ+π/2] x∈[kπ-π/3,kπ+π/6]

    单减区间为2x+π/6∈[2kπ+π/2,2kπ+3π/2] x∈[kπ+π/6,kπ+2π/3]

    2.若角α,β的终边不共线,且f(α)=f(β)

    则α,β之间相差π

    即α+β=2kπ+π

    所以tan(α+β)=tan(2kπ+π)=tanπ=0