Assisted Simplification with other equations?

I want to simplify an equation knowing certain other information. My equation is this:
syms b Q e gamma K_phi eta K_theta ao CL_delta delta_o CM_delta c ao
eqn = (ao*((CL_delta*Q)/ao - (Q^2*e*(tan(eta)*((CL_delta/ao + (CM_delta*c)/(ao*e))*((Q*b)/2 - cos(gamma)*sin(gamma)*(K_phi - K_theta)) + (CL_delta*b*(K_theta*cos(gamma)^2 - Q*e + K_phi*sin(gamma)^2))/(2*ao*e)) - (CL_delta/ao + (CM_delta*c)/(ao*e))*(K_phi*cos(gamma)^2 + K_theta*sin(gamma)^2 + (Q*b*tan(eta))/2) + (CL_delta*b*(cos(gamma)*sin(gamma)*(K_phi - K_theta) + Q*e*tan(eta)))/(2*ao*e)))/((K_phi*cos(gamma)^2 + K_theta*sin(gamma)^2 + (Q*b*tan(eta))/2)*(K_theta*cos(gamma)^2 - Q*e + K_phi*sin(gamma)^2) + (cos(gamma)*sin(gamma)*(K_phi - K_theta) + Q*e*tan(eta))*((Q*b)/2 - cos(gamma)*sin(gamma)*(K_phi - K_theta)))))/(CL_delta*Q);
I was told that using the below information that I can simplify eqn to be truely a function of gamma alone, but I cannot prove it or do it in MATLAB. The info is:
b/c = 6;
e/c = 0.1;
K_phi/K_theta = 3;
CL_delta/ao = 0.4805020381;
CM_delta/ao = -0.096610459;
eta = pi/6;

 채택된 답변

Torsten
Torsten 2023년 10월 10일
이동: Walter Roberson 2023년 10월 11일

2 개 추천

I was told that using the below information that I can simplify eqn to be truely a function of gamma alone
Since Q does not appear in your 6 conditions, this cannot be true.

댓글 수: 1

... Unless Q happens to appear in a way that cancels once you do the other substitutions. Which does not happen to be the case. The Q^2 in the numerator can be divided by the Q in the denominator, but that is going to leave a Q.

댓글을 달려면 로그인하십시오.

추가 답변 (1개)

Use subs() command and assign variables properly, e.g.:
syms b Q e gamma K_phi eta K_theta ao CL_delta delta_o CM_delta c ao
eqn = (ao*((CL_delta*Q)/ao - (Q^2*e*(tan(eta)*((CL_delta/ao + (CM_delta*c)/(ao*e))*((Q*b)/2 - cos(gamma)*sin(gamma)*(K_phi - K_theta)) + (CL_delta*b*(K_theta*cos(gamma)^2 - Q*e + K_phi*sin(gamma)^2))/(2*ao*e)) - (CL_delta/ao + (CM_delta*c)/(ao*e))*(K_phi*cos(gamma)^2 + K_theta*sin(gamma)^2 + (Q*b*tan(eta))/2) + (CL_delta*b*(cos(gamma)*sin(gamma)*(K_phi - K_theta) + Q*e*tan(eta)))/(2*ao*e)))/((K_phi*cos(gamma)^2 + K_theta*sin(gamma)^2 + (Q*b*tan(eta))/2)*(K_theta*cos(gamma)^2 - Q*e + K_phi*sin(gamma)^2) + (cos(gamma)*sin(gamma)*(K_phi - K_theta) + Q*e*tan(eta))*((Q*b)/2 - cos(gamma)*sin(gamma)*(K_phi - K_theta)))))/(CL_delta*Q);
display(eqn)
eqn = 
b = 6*c;
e = 0.1*c;
K_phi = 3*K_theta;
CL_delta = 0.4805020381*ao;
CM_delta = -0.096610459*ao;
eta = pi/6;
eqn=subs(eqn, b);
eqn=subs(eqn, e);
eqn=subs(eqn, K_phi);
eqn=subs(eqn, CL_delta);
eqn=subs(eqn, CM_delta);
eqn=subs(eqn, eta);
FINAL_eqn = eqn;
display(FINAL_eqn)
FINAL_eqn = 

댓글 수: 2

This is not going to be able to transform to an expression in just gamma. This is not the correct solution to the question asked, and Torsten had the correct answer.
Thank you both, I realized my mistake in the original expression and this command definitely will work for me.

댓글을 달려면 로그인하십시오.

카테고리

도움말 센터File Exchange에서 Mathematics에 대해 자세히 알아보기

제품

릴리스

R2022b

태그

질문:

2023년 10월 10일

댓글:

2023년 10월 11일

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by