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!
Step-by-step explanation:
x^2 + 10x = -25
x^2 + 10x + 25 = 0
(x+5)^2=0
x=-5
Answer:
-2x
Step-by-step explanation:
The expression itself is -2x. We subtract the coefficients 7 and 9 to get -2.
Answer:
.005
Step-by-step explanation: