We know that sin2x=2sinxcosx
(search the net for proof if you wish)
So the original equation becomes
2sinxcosx-sinx=0
The two terms both have sinx that can be taken out to get:
sinx(2cosx-1)=0
This is true if sinx=0 or 2cosx-1=0 , rewritten: cosx=1/2
sinx=0 than x=2kπ
cosx=1/2 than x=π/3+2kπ
where k is an integer
Answer:
6
Step-by-step explanation:
1. get rid of parentheses: 12x -6 = 10x +6
2. group like terns together: 12x-10x = 6+6
3. simplify: 2x = 12
4. divide both sides by 2: x=6
Answer:
a) 16%
b) 2.5%
Step-by-step explanation:
a)
The mean is 70 with standard deviation(SD) of 3 and you are asked to find out the percentage of staff that have <67(70-3 inch= mean - 1 SD) inch size, which means 1 SD below the mean (<-1 SD). Using 68-95-99.7 rule, you can know that 68% of the population is inside 1 SD range from the mean ( -1 SD to + 1 SD).
To put it on another perspective, there are 32% of the population that have < -1 SD and > +1 SD value. Assuming the distribution is symmetrical, then the value of < - 1 SD alone is 32%/2= 16%
b)
The question asks how many populations have size >76 inches, or mean + 2 SD (70+3*2 inch).
You can also solve this using 68-95-99.7 rule, but you take 95% value as the question asking for 2 SD instead. Since 95% of population is inside 2 SD range from the mean ( -2 SD to + 2 SD), so there are 5% of population that have < -2 SD and > +2 SD value. Assuming the distribution is symmetrical, then the value of > +2 SD alone is 5%/2= 2.5%
Answer:
5 candies
Step-by-step explanation:
Total of candy Sarah has = 25candies
If Sarah gave 2/5 of the candies to her sister, the total amount she gave her sister will be 2/5 of 25
2/5 of 25 = 10
The remaining candy left will be 25-10 which is 15.
If she gave 2/3 of amount left to her friend, the amount she gave her friend will be 2/3×15 = 10candies.
The amount of candy Sarah have left will be 15- 10 which is 5candies.
Answer:
(-1.703, 2.396)
(1.37, 6.493)
Step-by-step explanation:
We can easily solve this question by using a plotting tool or any graphing calculator,
The solution to the system of equation is given by the intersection points between the graphs of
y1 = −x^2 + x + 7
y2 = x^2 + 3x + 7
Please, see attached picture below.
The solutions are:
(-1.703, 2.396)
(1.37, 6.493)
