Melody

Here is another link

Good one Chris :)

That is an excellent result Dbg CONGRATULATIONS   

See, we all told you that there was nothing wrong with your English !

ok

I've toyed with it but I do not have a clue.    

$$\\f(x)=(x^2-4)-1\\
f(x)=x^2-5\\
f(1)=1^2-5\\
f(1)=1-5\\
f(1)=-4\\
if\;v=1\;then\;w=-4$$

I do it from scratch each time

$$\\180\;degrees=\pi radians\\
so\\
1\;degree=\frac{\pi}{180\;}radians\\
so\\
x\;degrees=\frac{\pi}{180\;}\times x \;\;\;radians\\$$

$$\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}{\left({\mathtt{48}}^\circ\right)}{\mathtt{\,\times\,}}{\mathtt{13}} = {\mathtt{8.698\: \!697\: \!882\: \!667}}$$

$$\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}{\left({\mathtt{48}}{\mathtt{\,\times\,}}{\mathtt{13}}\right)} = -{\mathtt{0.104\: \!528\: \!463\: \!268}}$$

I am surprised that there are no imaginary solutions for this.  

WolframAlpha sys that there are none.

Thanks DarkBlaze347

I like that you have not just given the answer :)

It is best when askers are expected to a little for themselves.   

I am not at all sure what youare talking about but there is a graph that might be relevant