Answer: cos(Θ) = (√15) / 4
Explanation:
The question states:
1) sin(Θ) = 1/4
2) 0 < Θ < π / 2
3) find cos(Θ)
This is how you solve it.
1) Use the fundamental identity (in this part I use α instead of Θ, just for facility of wirting the symbols, but they mean the same for the case).

2) From which you can find:

3) Replace sin(α) with 1/4
=>

=>

4) Given that the angle is in the first quadrant, you know that cosine is positive and the final answer is:
cos(Θ) =

.
And that is the answer.
Answer:
Step-by-step explanation:
I think you have the question incomplete, and that this is the complete question
sin^4a + cos^4a = 1 - 2sin^2a.cos^2a
To do this, we can start my mirroring the equation.
x² + y² = (x + y)² - 2xy,
This helps us break down the power from 4 to 2, so that we have
(sin²a)² + (cos²a)² = (sin²a + cos²a) ² - 2(sin²a) (cos²a)
Recall from identity that
Sin²Φ + cos²Φ = 1, so therefore
(sin²a)² + (cos²a)² = 1² - 2(sin²a) (cos²a)
On expanding the power and the brackets, we find that we have the equation proved.
sin^4a + cos^4a = 1 - 2sin^2a.cos^2a
Answer:
11
Step-by-step explanation:
Answer:
it's answer is 107
Step-by-step explanation:
firstly
x+28+45=180
x+73=180
x=180 subtract 73 = 107
Answer:
Yes
12, 35, 37
16, 30, 34
20, 21, 29
No
18, 24, 42
Step-by-step explanation:
Required
Determine which length form a right triangle
To do this, we make use of Pythagoras theorem where the square of the largest length = the sum of the squares of the other lengths
So:
(1) 12, 35, 37 --- Yes



(2) 16, 30, 34 --- Yes



(3) 18, 24, 42 --- No




(4) 20, 21, 29 -- Yes


