Just use the stats given and put them into the fomula
Answer: option D
Step-by-step explanation:
Remember the cosine identity:

Given the right triangle DFE shown in the image, you can identify that the adjacent side and the hypotenuse for the angle F of this triangle are:

Now you can substitute values into
and then reduce the fraction.
THerefore you get:
Denominator:

so excluded values are x = -1 and x = 1.
Answer D.
Answer:
x = 3
Step-by-step explanation:
2x - y = 4
x + y = 5
y = 5 - x
2x - (5 - x) = 4
2x + x - 5 = 4
3x = 9
x = 3
Answer:
x ≈ - 9.41, x ≈ - 6.59
Step-by-step explanation:
Given
x² + 16x + 62 = 0 ( subtract 62 from both sides )
x² + 16x = - 62
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(8)x + 64 = - 62 + 64
(x + 8)² = 2 ( take the square root of both sides )
x + 8 = ±
( subtract 8 from both sides )
x = - 8 ± 
Hence
x = - 8 -
≈ - 9.41
x = - 8 +
≈ - 6.59