Pleaseee help guys:(
2 answers:
Answer:
Step-by-step explanation:
Note that this looks like the identity:
cos(A + B) = cosAcosB - sinAsinB.
In this case, A = π/12 and B = 3π/4. So, we can say that the given equation:
cos(π/12)cos(3π/4) - sin(π/12)sin(3π/4) = cos(π/12 + 3π/4) = cos(π/12 + 9π/12) = cos(10π/12) = cos(5π/6)
Ah, now we have a trigonometry problem we can easily solve!
cos(5π/6) = -cos(π/6) = -(√3)/2
Hope this helps!
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Answer:
Option (4) and Option (5)
Step-by-step explanation:
By calculating the second difference, if the second difference in a table is equal, table will represent the quadratic relationship.
In the given option, we analyze that table given in Option (4) will represent the quadratic relationship.
x y Ist difference IInd difference
0 4 - -
1 -4 -4 - (4) = -8 -
2 -4 -4 - (-4) = 0 0 - (-8) = 8
3 4 4 - (-4) = 8 8 - 0 = 8
Second difference of the terms in y are the same as 8.
Therefore, table of Option (4) represents the quadratic relationship.
Similarly, in Option (5) we will calculate the second difference of y terms.
x y Ist difference IInd difference
0 -4 - -
1 -8 -8 - (-4) = -4 -
2 -10 -10 - (-8) = -2 -2 - (-4) = 2
3 -10 -10 - (-10) = 0 0 - (-2) = 2
Here the second difference is same as 2.
Therefore, table of Option (5) will represent the quadratic relationship.