Simplifying trig expressions

[parisse]

(04-26-2022 07:05 PM)csplinter Wrote:  This has long been one of my biggest issues using the HP Prime. I'll start with an example.

I do several calculations and end up with something like

81*sqrt(cos(v)^2 *sin(u)^4 +(cos(v)^2 -sin(v)^2)^2 *cos(u)^2 *sin(v)^2 +(cos(v)^2 -sin(v)^2)^2 *sin(u)^2

I know that this should simplify to 81*sin(u) or something like this.

I doubt this simplifies to something simple. Perhaps you made an error before entering the computation, or there is a relationship between u and v.

Quote:I've tried simplify(), tcollect(), trigsin(), factor() and all kinds of random functions, but can't seem to get anything more readable. Why can't the HP Prime seem to recognize cos(x)^2+sin(x)^2 = 1?

trigsin/trigcos/trigtan just do that and return an expression that favor respectively sin/cos/tan.