I am trying to get wxMaxima to give me arcsin(4/5), either in radians or degrees. I am using

Question

a: 4/5$
b:asin(a)$
print("the angle is ", b)$

But it returns

the angle is asin(4/5)

How do I get wxMaxima to give me the angle? I want .927 radians or 53.1 degrees.

Answer 1

Hmm. don't know wxMaxima, but have you tried something like

print("the angle is ", b+0)$

so it has to evaluate b.

Answer 2

Using b+0 doesn't phase it. The problem is getting wxMaxima to make 4/5 into a decimal. If I use

a: 0.8$
b: asin(a)$
print("the angle is ", b)$

Then it works. It gives me
the angle is 0.92729521800161

But if I try to convert that to degrees:

c: b*180/%pi$
print("the angle is ", c, " degrees")$

it returns

the angle is 166.9131392402902/%pi degrees

There is some setting to make it evaluate ratios as approximate decimal numbers, but I don't know what it is, and have not yet found it in the labriynths of maxima help.

Answer 3

using online maxima, I found also that

acos(.8)*180/%pi;
does what you show, but

acos(.8)*180/%pi,numer;

produces 36.86...

as the answer in degrees. Maybe wxMaxima has something similar

Answer 4

I see. A trailing ,numer; works.
For asin(.8),

asin(.8)*180/%pi, numer;

produces 53.13...

I also found that writing numbers with a trailing .0 forces approximation. And for the built-in constants, float() forces approximation. For example:

a: 4.0/5.0$
disp(a)$
b: asin(a)$
print("the angle is ", b, " radians")$
c: float(b*180 / %pi)$
print("the angle is ", c, " degrees") /* works */$

returns

the angle is 0.92729521800161 radians
the angle is 53.13010235415599 degrees

Where is online Maxima?

Thank you for the help.