MaplePrimes - answers and comments on Question, numeric solutions vector for a trigonometric equation

with(RootFinding)

Adri vanderMeer van der Meer — Wed, 20 Jun 2012 11:34:03 Z

See ?RootFinding,NextZero
I take N=10 and suppose that you only want positive solutions.

restart; with(RootFinding):
eq1:=(8/x)=tan(7*x/50):
f := unapply( lhs(eq1)-rhs(eq1), x ):
X := Vector(10):
X[1] := NextZero(f,0): 
for i from 2 to 10 do X[i] := NextZero(f, X[i-1] ) end do:

This gives you a vector X, containing the first ten solutions.
(By the way, of course the n'th solution X_n is not X₁ + n π.)

Missed positive zero

Markiyan Hirnyk — Thu, 21 Jun 2012 08:16:09 Z

> fsolve(8/x=tan(7*x*(1/50)), x = 4 .. 9);

6.400256151
PS. Your sequence begins from 24.67904374.

Executed worksheet

Adri vanderMeer van der Meer — Thu, 21 Jun 2012 11:37:41 Z

@Markiyan Hirnyk This is Maple 14

Zeros.mw

I see

Markiyan Hirnyk — Thu, 21 Jun 2012 12:14:17 Z

@Adri vanderMeer van der Meer I didn't display X.