(1)直接代入计算就是了,x/3-π/6=π/4所以f(x)=√2
(2)代入条件可得:sinα=5/13,sin(β+π/2)=cosβ=3/5,由于α,β∈[0,π/2],
cosα=12/13.sinβ=4/5,
cos(α+β)=cosαcosβ-sinαsinβ=16/65
(1)直接代入计算就是了,x/3-π/6=π/4所以f(x)=√2
(2)代入条件可得:sinα=5/13,sin(β+π/2)=cosβ=3/5,由于α,β∈[0,π/2],
cosα=12/13.sinβ=4/5,
cos(α+β)=cosαcosβ-sinαsinβ=16/65