# Question:tan won't evaluate?

## Question:tan won't evaluate?

Maple
I've got a block of code that I use once in a simple form, and then a second time in a more cascaded form but the second bunch doesn't work. And it seems as though tan won't evaluate numerically for me - it's really bugging me. Maple 11. Here's the block of code that does work: > eqn := Zin = (70.71*(100+(70.71*I)*tan(2*Pi*f/(3*10^8)*0.25e-1)))/(70.71+(100*I)*tan(2*Pi*f/(3*10^8)*0.25e-1)); > eqn1 := GAMMA[i] = (Zin-50)/(Zin+50); > eqn2 := (1+abs(GAMMA[i]))/(1-abs(GAMMA[i])); > sol := subs(eqn, eqn1); > sol1 := subs(sol, eqn2); > unapply(sol1, f); > plot(sol1, f = 10^9 .. 8*10^9, y = .9 .. 2.2, numpoints = 200); Here's the large group of code that doesn't work. Same principles. When I check each of the steps though with evalf the tan function doesn't actually give me a number. Both in the upper code block that does work, and in the bottom. eq1 := Z1 = (91.68*(100+(91.68*I)*tan(2*pi*f/(3*10^8)*0.25e-1)))/(91.68+(100*I)*tan(2*pi*f/(3*10^8)*0.25e-1)) eq2 := Z2 = (70.7*(Z1+(70.7*I)*tan(2*pi*f/(3*10^8)*0.25e-1)))/(70.7+I*Z1*tan(2*pi*f/(3*10^8)*0.25e-1)) eq3 := Z3 = (54.5*(Z2+(54.5*I)*tan(2*pi*f/(3*10^8)*0.25e-1)))/(54.5+I*Z2*tan(2*pi*f/(3*10^8)*0.25e-1)) eq4 := GAMMA[i] = (Z3-50)/(Z3+50) eq5 := (1+abs(GAMMA[i]))/(1-abs(GAMMA[i])) soln1 := subs(eq1, eq2) soln2 := subs(soln1, eq3) soln3 := subs(soln2, eq4) soln4 := subs(soln3, eq5) unapply(soln4, f) plot(soln4, f = 10^9 .. 8*10^9, y = .9 .. 2.2,numpoints=200)
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