I need help with this equation:
sin(x)cos(x)tan(x)=1-cos^2(x)
Hi
substitute $\displaystyle \frac{sinx}{cosx} $ for tanx.
This will give you
$\displaystyle sinx*cosx*\frac{sinx}{cosx}= 1 - cos^2x $
as you can see the cosx will cancel on the left side of the equal sign.
This leaves you with
$\displaystyle sin^2x = 1 - cos^2x $
and you know the trig identity of $\displaystyle sin^2x + cos^2x = 1 $
Does that clear everything up for you?