Answer:
55%
Step-by-step explanation:
Since Anna earned 22 points, and there was a total of 40 points, this means that she scored 22 out of 40 points. You can simplify this by dividing the denominator and numerator by 2. Then, you can multiply both the numerator and denominator by 5 to get a number out of 100.
9514 1404 393
Answer:
D
Step-by-step explanation:
In the second quadrant, ...
c = 180° -arcsin(24/25) ≈ 106.26°
In the third quadrant, ...
d = 360° -arccos(-3/4) ≈ 221.41°
Then cos(c+d) = cos(327.67°) ≈ 0.84498
This is a positive irrational number, greater than 21/100, so the only reasonable choice is the last one:
_____
Perhaps you want to work this out using the trig identities.
cos(c) = -√(1 -sin(c)²) = -7/25
sin(d) = -√(1 -cos(d)²) = -(√7)/4
Then the desired cosine is ...
cos(c+d) = cos(c)cos(d) -sin(c)sin(d)
cos(c+d) = (-7/25)(-3/4) -(24/25)(-√7/4)
cos(c+d) = (21 +24√7)/100 . . . . matches choice D