Items tagged with trigonometry trigonometry Tagged Items Feed

Hello,

I would like to solve this equation :

tan(gamma0(t)) = tan(gamma[1](t)-theta[1](t)-psi[1](t)

I would like to select the solution of arctan by assuming the domain of variation of some variables. In my case, if -Pi/2 < gamma[1](t) - theta[1](t) - psi[1](t) < Pi/2, the arctan gives only one solution.

Can you help me to solve this equation ? 

eq:=tan(gamma0(t)) = tan(gamma[1](t)-theta[1](t)-psi[1](t))
solve(eq,gamma0(t)) assuming -Pi/2 < gamma[1](t) - theta[1](t) - psi[1](t) < Pi/2

I guess that I don't use properly the "assume" function.

The result that I would like to obain is quiet simple :

gamma0(t)) = gamma[1](t)-theta[1](t)-psi[1](t)

Thanks a lot for your help

 

Hello,

I have still some difficulties to conduct some specific trigonometric simplications but which are very common in mechanism study.

The equations are in the form :

sin(gamma0(t))*cos(beta0(t)) = -(sin(psi[1](t))*cos(theta[1](t))*cos(gamma[1](t))+sin(psi[1](t))*sin(theta[1](t))*sin(gamma[1](t))-cos(theta[1](t))*cos(psi[1](t))*sin(gamma[1](t))+cos(psi[1](t))*sin(theta[1](t))*cos(gamma[1](t)))*cos(beta[1](t))

I would like to obtain this equation after simplifications :

sin(gamma0(t))*cos(beta0(t)) = cos(beta[1](t))*sin(gamma[1](t)-theta[1](t)-psi[1](t))

I try to make a procedure to automatize the simplification of this kind of trigonometric equation.

Strangely, I noticed that the simplification is done only if there is a minus before the combine function. The simplification works but the result is wrong because i didn't obtain the good sign.

For you information, I try to make these simplifications with MMA and the FullSimplify function of MMA gives directly the expected result that is to say :

I'm sure that it shoud exist a good way to conduct this kind of simplications in Maple.

Can you help me to correct my procedure so to obtain the good result and be enough general, adaptative ? 

Code here and attached in this post :

Initialisation
restart:
with(LinearAlgebra):
with(Student[MultivariateCalculus]):
with(plots):
with(MathML):
with(ListTools):
constants:= ({constants} minus {gamma})[]:
`evalf/gamma`:= proc() end proc:
`evalf/constant/gamma`:= proc() end proc:
unprotect(gamma);
Angular Constraint equations
eq_liaison:=sin(gamma0(t))*cos(beta0(t)) = -(sin(gamma[1](t))*sin(psi[1](t))*sin(theta[1](t))-sin(gamma[1](t))*cos(theta[1](t))*cos(psi[1](t))+cos(gamma[1](t))*sin(psi[1](t))*cos(theta[1](t))+cos(gamma[1](t))*cos(psi[1](t))*sin(theta[1](t)))*cos(beta[1](t)); 
Traitement
TrigoTransform2:= proc(Eq)
local S,S1,tt,pp,Eq2,ListVariables,ListVariablesMod,Subs,size,rhsEq2,lhsEq2;
#Construit une liste à plat#
ListVariables:=indets(Eq, function(identical(t)));
ListVariables:=[op(ListVariables)];
ListVariablesMod:=map(f->cat(op(0,f),_),ListVariables);
Subs:=ListVariables=~ListVariablesMod;
#Variables Changement#
Eq2:=Eq:
print("Equation traitée=",Eq2): 
Eq2:=subs(Subs, Eq2);
print("Equation après subs=",Eq2): 
#Trigonometric transformations#
lhsEq2:=applyrule([
cos(u::anything)*cos(v::anything)-sin(u::anything)*sin(v::anything)=cos(u+v), 
cos(u::anything)*sin (v::anything)+sin(u::anything)*cos(v::anything)=sin(u+v), 
sin(u::anything)*sin(v::anything)-cos(u::anything)*cos(v::anything)=-cos(u+v), 
-sin(v::anything)*cos(u::anything)-sin(u::anything)*cos(v::anything)=-sin(u+v)], simplify(lhs(Eq2), size));
print("Equation lhsEq2 première analyse=",lhsEq2):
rhsEq2:=applyrule([
cos(u::anything)*cos(v::anything)-sin(u::anything)*sin(v::anything)=cos(u+v), 
cos(u::anything)*sin (v::anything)+sin(u::anything)*cos(v::anything)=sin(u+v), 
sin(u::anything)*sin(v::anything)-cos(u::anything)*cos(v::anything)=-cos(u+v), 
-sin(v::anything)*cos(u::anything)-sin(u::anything)*cos(v::anything)=-sin(u+v)], simplify(rhs(Eq2), size));
print("Equation rhsEq2 première analyse=",rhsEq2):
try
lhsEq2:=(trigsubs(2*combine(lhsEq2))[])/2;
print("Equation lhsEq2=",lhsEq2):
catch:
lhsEq2:=lhs(Eq2);
end try;
try
rhsEq2:=(trigsubs(-2*combine(rhsEq2))[])/2;
print("Equation rhsEq2=",rhsEq2):
catch:
rhsEq2:=rhs(Eq2);
end try;
Eq2:= lhsEq2=rhsEq2;
#Variables Changement#
Eq2:=subs(map(t->rhs(t)=lhs(t),Subs),Eq2) 
end proc:
TrigoTransform2(eq_liaison);

TrigoTransformEqAng2_anglais.mws

Thanks a lot for your help.

I don't know if I am doing it right or not because Maple isn't solving the equation. The equation solution is x=2^(1/2).

Here I let a picture of which equation I want to solve and Maple's response.

Trigonometric Equation

So it looks like radians work.

Why does degrees fail and how do I get degrees work?

How do you guys like to access pi? Do you keep a symbol of it around in a random document to open? 

 

http://i.imgur.com/07o1dyH.png

Let A(x , 2 , -1) ,B(0, y , 1) ,C(3 , 4 , -2) , AB=AC and ABC is isosceles right triangle. Find x and y ?

I am attempting to plot an initial value problem in Maple 18.  I have my equation defined, as well as a general solution and two particular solutions at y(0)=3/4 and y(0)=1/2.  To graph, I entered the command

DEplot(de,y(x),x=-3..3,{[0,1/2],[0,3/4]},dirgrid=[12,12],color=black,linecolor=blue,thickness=2);

but instead of returning a graph, the software gave me the error message

Error, (in DEtools/DEplot/CheckDE) extra unknowns found: sinx

The Maple support site lists this as an unknown error, and as a new user, I'm not sure what to do.  What does this mean?

Hello

 

I have this kind of expression :

exppr

I would like to keep a sum like and simplify all the expressions of
the type $z+\bar{z}=2Re(Z)$

 

Thanks for your suggestion

True of False, Explain:

If ∏/2<θ<∏, Then cos θ/2<0

Find the value: P=sin(10)sin(30)sin(50)...sin(890) ?

How do you express sin(4x)^2 in terms of powers of cos(x) in Maple 17?

My question is in the title, here is simple example: 

K:=(sin^2(a+b)-sin^2(a-b))

I use formula of abridged multiplication (with help of "factor")

>factor(K)

  (sin(a+b) - sin(a-b))(sin(a+b) + sin(a-b))

Then expand:

>expand(%, trig)

  4sin(a)cos(b)cos(a)sin(b)

And all I whant now is to use double angle formula like this:

4sin(a)cos(b)cos(a)sin(b) = sin(2a)sin(2b)

I am trying to use the procedure described in the answers to this question: 

http://www.mapleprimes.com/questions/100137-Solving-Trigonometric-Equations-For

to find the solutions to sin(2*x) = 1/2 where -2*Pi <= x <= 2*Pi. After the isolve() command is issued, I get the warning that solutions may have been lost. i think the issue is the form in which Maple represents the general solution to the equation. Any ideas on how to rectify this would be greatly appreciated!

Dear friends,

I have recently been calculating a sum from this link.

The problem here is to calculate the sum sum_{n>=1} (-1)^(n+1)/(n^2+a) with a some positive real number. You probably all agree that it is preferable to express it using elementary functions from basic calculus as opposed to the Gamma, Zeta and Digamma...

 

How to solve it with Maple? The explicit and nonnumerical solution is required.

1 2 Page 1 of 2