Answer: sin = ±
Step-by-step explanation:
We very well know that,
cos2A=1−2sin²A
⟹ sinA = ±
As required, set A = & cos a= ,thus we get
sin =±
∴ sin =± = ±
since ,360° < <450°
,180° < <225°
Now, we are to select the value with the correct sign. It's is obvious from the above constraints that the angle a/2 lies in the III-quadrant where 'sine' has negative value, thus the required value is negative.
hope it helped!
Answer:
492.99
Step-by-step explanation: x = amount invested at 12%
y = amount invested at 9%
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x + y = 20287
0.12x = 0.09y + 492.99
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put the system of linear equations into standard form
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x + y = 20287
0.12x - 0.09y = 492.99
T= MN+R
I believe that this is the right answer