differentiate arccos

[south heath]

.

answer is, but idk where the positive sign is dropped

[fair basalt]

you are not meant to square both sides

use the fact that siny = root (1-x ^2)

[south heath]

why can we ignore the the - though?

siny=root(1-x^2) is from s^2+c^2=1
so s=+-root(1-c^2) right?

[fair basalt]

as it was orignally sin squared, we are only looking at the positve bit of the graph

if u imagine it graphically

[south heath]

i c