Answer:
Jan brought 44 cookies
Step-by-step explanation:
To solve this problem, we need to work backwards. First, we have 10 cookies left at the end of the day. At lunch, she gave away 12 cookies. This means that Ms. Jan had 22 cookies at lunch since
10
+
12
=
22
In the morning, Ms. Jan gave out half of her cookies. This means that she started with twice as many cookies as she had at the beginning of lunch.
22 x 2
=
44
Ms. Jan brought 44 cookies.
arcsin(1/2) means "the angle whose sine is 1/2".
That's 30° .
y = cos(30°) = (1/2)√3 = about 0.866 .
