Question

How do you simplify `cos((3pi)/2-x)`?

Answer 1

`-sinx`

Explanation:

`"using the "color(blue)"addition formulae for cosine"`

`•color(white)(x)cos(A+-B)=cosAcosB∓sinAsinB`

`rArrcos((3pi)/2-x)`

`=cos((3pi)/2)cosx+sin((3pi)/2)sinx`

`=0cosx+(-1)sinx`

`=-sinx`