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:
The first step is A. Subtraction
The second steep is D. Division
Step-by-step explanation:
The first step was done in other to remove the constant at one end of the equality that was with the variable, it was done in order to eradicate the constant and isolate the variable to make the equation easier to solve.
The second step was done in order to remove the coefficient of the variable so as the variable to be on it's own as x alone.
These two steps were just followed in order to find the value of the variable.
Answer:
10000
Step-by-step explanation:
it is 10000 because 1 kilometer is a thousand meters
3.6x - 2y = 6
-2.7x + y = 3.....multiply by 2
----------------
3.6x - 2y = 6
-5.4x + 2y = 6 (result of multiplying by 2)
----------------add
-1.8x = 12
x = 12/-1.8
x = - 6.67 (or -20/3)
3.6x - 2y = 6
3.6(-6.67) - 2y = 6
-24.01 - 2y = 6
-24.01 - 6 = 2y
-30.01 = 2y
-30.01 / 2 = y
-15 = y
solution : (-6.67, -15)
Answer:
I like baseball
Step-by-step explanation:
because I like baseball
