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:
200 pairs of sandals
Step-by-step explanation:
Represent the sandals with x and the running shoes with y.
In a typical month:
In April
Required
The number of sandals in a typical month
<u>In a typical month:</u>
If 1 sandal costs 2.50, then x costs 2.50x
If 1 running shoe costs 4, then y costs 4y
The total is:
<u>In April:</u>
If 1 sandal costs 2.50, then 2x costs 5x ---- <em>we used 2x because the pairs is doubled </em>
If 1 running shoe costs 4, then y costs 4y
The total is:
The equations are:
Subtract