Answer:
cos(F) = 9/41
Step-by-step explanation:
The triangles are similar, so you know that ...
... cos(D) = cos(A) = 40/41.
From trig relations, you know ...
... cos(F) = sin(D)
and
... sin(D)² +cos(D)² = 1
So ...
... cos(F) = sin(D) = √(1 -cos(D)²) = √(1 -(40/41)²) = √(81/1681)
... cos(F) = 9/41
_____
The ratio for cos(A) tells you that you can consider AB=40, AC=41. Then, using the Pythagorean theorem, you can find BC = √(41² -40²) = √81 = 9.
From the definition of the cosine, you know cos(C) = BC/AC = 9/41. Because the triangles are similar, you know
... cos(F) = cos(C) = 9/41
It could be D or C
The system has two solutions
x = .8 y = .6
OR if you think about it , (x=.8 y=.6) could be considered THE solution.
I would go with choice C
Answer:
Give me more information
Step-by-step explanation:
we have
Factor the leading coefficient
Complete the square. Remember to balance the equation by adding the same constants to each side
Divide both sides by 
Rewrite as perfect squares
Taking the square roots of both sides (square root property of equality)
Remember that
<u>the answer is</u>
The solutions are
