2 1/4 + 1 2/4 ≠ 5
Why?
2 1/4 + 1 2/4
=3 3/4
The answer is wrong because the student added wrong. The real answer is 3 3/4.
Answer:
A. false
B. true
C. true
D. false
step-by-step:
A: probability of spinning a 4 on spinner A is 1/4 and probability of spinning a 4 on spinner B is 1/3.
B: there are 2 fours out of 6 possible options so that makes it 2/6, simplify that, it becomes 1/3.
C: 2 and 4 are even numbers so that makes 2/4 possible on spinner A. simplify 2/4 and that becomes 1/2.
D. spinning a 3 on spinner A would make it 1/4 (already simplified). spinning a 3 on spinner B would make it 1/6 (already simplified) therefore spinner A is greater.
Answer:
54
Step-by-step explanation:
Answer:
204/325
Step-by-step explanation:
You can work this a couple of ways. We expect you are probably expected to use trig identities.
cos(A) = √(1 -sin²(A)) = 24/25
sin(B) = √(1 -cos²(B)) = 12/13
cos(A -B) = cos(A)cos(B) +sin(A)sin(B) = (24/25)(5/13) +(7/25)(12/13)
= (24·5 +7·12)/325
cos(A -B) = 204/325
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The other way to work this is using inverse trig functions. It is necessary to carry the full calculator precision if you want an exact answer.
cos(A -B) = cos(arcsin(7/25) -arccos(5/13)) = cos(16.2602° -67.3801°)
= cos(-51.1199°) ≈ 0.62769230 . . . . (last 6 digits repeating)
The denominators of 25 and 13 suggest that the desired fraction will have a denominator of 25·13 = 325, so we can multiply this value by 325 to see what we get.
325·cos(A-B) = 204
so, the exact value is ...
cos(A -B) = 204/325
