Answer:
3/5
Step-by-step explanation:
We need to use the trig identity that cos(2A) = cos²A - sin²A, where A is an angle. In this case, A is ∠ABC. Essentially, we want to find cos∠ABC and sin∠ABC to solve this problem.
Cosine is adjacent ÷ hypotenuse. Here, the adjacent side of ∠ABC is side BC, which is 4 units. The hypotenuse is 2√5. So, cos∠ABC = 4/2√5 = 2/√5.
Sine is opposite ÷ hypotenuse. Here, the opposite side of ∠ABC is side AC, which is 2 units. The hypotenuse is still 2√5. So sin∠ABC = 2/2√5 = 1/√5.
Now, cos²∠ABC = (cos∠ABC)² = (2/√5)² = 4/5.
sin²∠ABC = (sin∠ABC)² = (1/√5)² = 1/5
Then cos(2∠ABC) = 4/5 - 1/5 = 3/5.
Answer:
The co-factors and their values are shown in the table below.
Step-by-step explanation:
We are given the matrix, 
.
It is required to match the co-factors with the corresponding values.
As, the co-factors are given by,
= 
, where the d= determinant of the matrix after removing the i- row and j- column.
So, we have,
1. 
.
So, 
i.e. 
2. 
.
So, 
i.e. 
3. 
.
So, 
i.e. 
4. 
.
So, 
i.e. 
5. 
.
So, 
i.e. 
Thus, we get,
Co-factor Value
16
27
-2
-5
-22
Answer:
C, 15 yd
Step-by-step explanation:
Hope this helps
Answer:
there is no solution for (0, 30°)
Step-by-step explanation:
six(x) = cos(x)
sin(x) - cos(x) = 0
(sin(x) - cos(x))^2 = 0
sin(t)^2 + cos(x)^2 - 2sin(x)cos(x) = 0
1 - sin(2x) = 0
sin(2x) = 1
2x = π/2 + 2πk -> k - any integer number
x = π/4 + πk
the smallest positive solution is π/4 = 45°. That means for range (0, 30°)
there is no solution
