[SIZE=4]If A=sin(-1)x, where x>0 sin(-1)x means the shift sin in the calulator of angle x
[SIZE=5]Two part question
a)show that cosA=squareroot of 1-x^2
If:
then:
but:
,
so:
.
Rearranging gives:
Now as , , and so , so we
want the positive square root in the last equation so: