cos4x = cos2x
We know that:
cos2x = 1-2cos^2 x
==> cos4x = 1-2cos^2 (2x)
Now substitute:
==> 1-2cos^2 (2x) = cos2x
==> 2cos^2 (2x) + cos2x - 1 = 0
Now factor:
==> (2cos2x -1)(cos2x + 1) = 0
==> 2cos2x -1 = 0 ==> cos2x =1/2 ==> 2x= pi/3
==> x1= pi/6 , 7pi/6
==> x1= pi/6 + 2npi
==> x2= 7pi/6 + 2npi
==> cos2x = -1 ==> 2x= pi ==> x3 = pi/2 + 2npi.
<span>==> x= { pi/6+2npi, 7pi/6+2npi, pi/2+2npi}</span>
Answer:
E. 396/538
Step-by-step explanation:
The probability that the senior selected will not be from High School B given that the senior did not answer colege:
First, what's the probability of not having answered college? This will be out denominator.
P(not choosing college) = 244 + 106 + 188 = 538
Next, what's the probability that a senior in that category is not from HS B? Well, add the probabilities that the senior is in HS A or C:
P(senior is in HS A or C and answered not college) = 49 + 99 + 63 + 83 + 31 + 71 = 396
<u>Our answer is E. 396/538.</u>
Answer:
6x + 2
Explanation:
4 + -2 = 2 and x + 3x + 2x = 6x
Answer:
594 square feet
Step-by-step explanation:
Area of a rectangle is length times width. We can find the area of each workers plot by multiplying 9 and 11 to get 99 sq feet. There is six workers, and therefore six plots of land, so we'd take our 99 sq feet and count that six times to get 594 square feet.
