双曲線余弦関数

using Plots

#x軸の目盛に π を使うための設定.
xticks_values = [-2π,-3π/2,-π,-π/2,0,π/2,π,3π/2,2π]
xticks_labels = ["-2π","-3π/2","-π","-π/2","0","π/2","π","3π/2","2π"]

plot(cosh,label=nothing,xticks = (xticks_values,xticks_labels),aspect_ratio=1,xlim=(-2π,2π),ylim=(0,10),lw=4)


#グラフに水平線を入れる
hline!([0]; label="", color=:black)
#グラフに垂直線を入れる
vline!([0]; label="", color=:black)