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....
Answer:
The first term of the sequence is 1/5
Step-by-step explanation:
The first term is 1/5.
The reason is that there is a common ratio between each term. In this case multiplying the previous term in the sequence by 5 would give the next term.
So in this case 1/5 is the first term.
If we multiply 1/5 by 5, it will give the next term which is 1.
1/5*5=1
Thus the first term in the sequence = 1/5....
Answer:
-G + 15 = - 2G + 23
- 15 -15
-G = -2G + 8
+2G +2G
S0, G = 8 is the answer
Step-by-step explanation:
Answer:
It increases x3.
Step-by-step explanation:
Let's say the fraction to begin with was 100/100. Ignore the fact that it isn't fully reduced and it is an improper fraction.
10% of 100 is 10, so the numerator is now 90 (decrease=get smaller; 100-10=90).
70% of 100 is 70, so the denominator is now 30 (decrease=get smaller; 100-70=30).
Our fraction is now 90/30 which, when fully reduced, equals 3.00. Since 100/100 equals 1.00, it has increased by 2.00 (3x bigger).
The answer is 72 because 720 divided by 10 is 72.