The answer in itself is 1/128 and here is the procedure to prove it:
cos(A)*cos(60+A)*cos(60-A) = cos(A)*(cos²60 - sin²A)
<span>= cos(A)*{(1/4) - 1 + cos²A} = cos(A)*(cos²A - 3/4) </span>
<span>= (1/4){4cos^3(A) - 3cos(A)} = (1/4)*cos(3A) </span>
Now we group applying what we see above
<span>cos(12)*cos(48)*cos(72) = </span>
<span>=cos(12)*cos(60-12)*cos(60+12) = (1/4)cos(36) </span>
<span>Similarly, cos(24)*cos(36)*cos(84) = (1/4)cos(72) </span>
<span>Now the given expression is: </span>
<span>= (1/4)cos(36)*(1/4)*cos(72)*cos(60) = </span>
<span>= (1/16)*(1/2)*{(√5 + 1)/4}*{(√5 - 1)/4} [cos(60) = 1/2; </span>
<span>cos(36) = (√5 + 1)/4 and cos(72) = cos(90-18) = </span>
<span>= sin(18) = (√5 - 1)/4] </span>
<span>And we seimplify it and it goes: (1/512)*(5-1) = 1/128</span>
Answer:
40
Step-by-step explanation:
no. of defective light bulbs= 8/100×500
= 40
The least common denominator is the Least Common Multiple (LCM) of the divisors 3 and 4. Since these numbers have no common factors, their LCM is
... 3·4 = 12
The least common denominator of your fractions is 12.
... 1/3 = (1/3)·(4/4) = 4/12
... 3/4 = (3/4)·(3/3) = 9/12
Answer:
X = 60
Y = 50
Step-by-step explanation:
The total degrees of a triangle is 180 degrees. For the middle triangle, 50+70=120 so 180-120=60.
On the far right, Y=50 because you take 50 degrees from the middle triangle, and insert it there.
