Answer:
[tex]^+_-\frac{\sqrt{7}}{2}.[/tex]
Step-by-step explanation:
[tex]1.| \ sinx+cosx| =\sqrt{(sinx+cosx)^2}=\sqrt{sin^2x+2sinxcosx+cos^2x}=\sqrt{1+2sinxcosx};[/tex]
2) according to the item 1:
[tex]sinx+cosx=^+_-\sqrt{1+2*\frac{3}{8}} =^+_-\sqrt{\frac{7}{4}}=^+_-\frac{\sqrt{7} }{2}.[/tex]