Sin³ x-sin x=cos ² x
we know that:
sin²x + cos²x=1 ⇒cos²x=1-sin²x
Therefore:
sin³x-sin x=1-sin²x
sin³x+sin²x-sin x-1=0
sin³x=z
z³+z²-z-1=0
we divide by Ruffini method:
1 1 -1 -1
1 1 2 1 z=1
-------------------------------------
1 2 1 0
-1 -1 -1 z=-1
--------------------------------------
1 1 0 z=-1
Therefore; the solutions are z=-1 and z=1
The solutions are:
if z=-1, then
sin x=-1 ⇒x= arcsin -1=π+2kπ (180º+360ºK) K∈Z
if z=1, then
sin x=1 ⇒ x=arcsin 1=π/2 + 2kπ (90º+360ºK) k∈Z
π/2 + 2kπ U π+2Kπ=π/2+kπ k∈Z ≈(90º+180ºK)
Answer: π/2 + Kπ or 90º+180ºK K∈Z
Z=...-3,-2,-1,0,1,2,3,4....
Since Christi earns $21 per hour, to find how much she earns by working 19 hours per week we need to multiply the hourly wage by the number of hours she works in a week:

Her weekly wage is $399
Answer: D) $399
Answer:
30 centimeters
Step-by-step explanation:
12 times 2.5 = 30
Answer:
Sum angle of triangle BHD = 180°
36 + 39 + BHD = 180
BHD = 180 - 36 - 39
= 105°
BHD + x° = 180° (straight angle)
105° + x° = 180°
x = 180 - 105
= 75°
Answer:
<u>Yes, it is 30</u>
Step-by-step explanation:
And yes, you thought it through correctly. 6(X-Y) = 6*5
6(X-Y) = <u>30</u>